Merge branch 'develop' of https://github.com/nlohmann/json into issue2592

test/src/UBSAN.supp

@@ -1 +0,0 @@
-unsigned-integer-overflow:stl_bvector.h

test/src/unit-algorithms.cpp

@@ -43,7 +43,7 @@ TEST_CASE("algorithms")
         {
             CHECK(std::all_of(j_array.begin(), j_array.end(), [](const json & value)
             {
-                return value.size() > 0;
+                return !value.empty();
             }));
             CHECK(std::all_of(j_object.begin(), j_object.end(), [](const json & value)
             {
@@ -67,7 +67,7 @@ TEST_CASE("algorithms")
         {
             CHECK(std::none_of(j_array.begin(), j_array.end(), [](const json & value)
             {
-                return value.size() == 0;
+                return value.empty();
             }));
             CHECK(std::none_of(j_object.begin(), j_object.end(), [](const json & value)
             {

test/src/unit-allocator.cpp

@@ -40,12 +40,12 @@ template<class T>
 struct bad_allocator : std::allocator<T>
 {
     template<class... Args>
-    void construct(T*, Args&& ...)
+    void construct(T* /*unused*/, Args&& ... /*unused*/)
     {
         throw std::bad_alloc();
     }
 };
-}
+} // namespace
 
 TEST_CASE("bad_alloc")
 {
@@ -85,10 +85,8 @@ struct my_allocator : std::allocator<T>
             next_construct_fails = false;
             throw std::bad_alloc();
         }
-        else
-        {
-            ::new (reinterpret_cast<void*>(p)) T(std::forward<Args>(args)...);
-        }
+
+        ::new (reinterpret_cast<void*>(p)) T(std::forward<Args>(args)...);
     }
 
     void deallocate(T* p, std::size_t n)
@@ -98,10 +96,8 @@ struct my_allocator : std::allocator<T>
             next_deallocate_fails = false;
             throw std::bad_alloc();
         }
-        else
-        {
-            std::allocator<T>::deallocate(p, n);
-        }
+
+        std::allocator<T>::deallocate(p, n);
     }
 
     void destroy(T* p)
@@ -111,10 +107,8 @@ struct my_allocator : std::allocator<T>
             next_destroy_fails = false;
             throw std::bad_alloc();
         }
-        else
-        {
-            p->~T();
-        }
+
+        p->~T();
     }
 
     template <class U>
@@ -133,7 +127,7 @@ void my_allocator_clean_up(T* p)
     alloc.destroy(p);
     alloc.deallocate(p, 1);
 }
-}
+} // namespace
 
 TEST_CASE("controlled bad_alloc")
 {
@@ -239,9 +233,9 @@ namespace
 template<class T>
 struct allocator_no_forward : std::allocator<T>
 {
-    allocator_no_forward() {}
+    allocator_no_forward() = default;
     template <class U>
-    allocator_no_forward(allocator_no_forward<U>) {}
+    allocator_no_forward(allocator_no_forward<U> /*unused*/) {}
 
     template <class U>
     struct rebind
@@ -256,7 +250,7 @@ struct allocator_no_forward : std::allocator<T>
         ::new (static_cast<void*>(p)) T(args...);
     }
 };
-}
+} // namespace
 
 TEST_CASE("bad my_allocator::construct")
 {

test/src/unit-alt-string.cpp

@@ -152,7 +152,7 @@ class alt_string
   private:
     std::string str_impl {};
 
-    friend bool ::operator<(const char*, const alt_string&);
+    friend bool ::operator<(const char* /*op1*/, const alt_string& /*op2*/);
 };
 
 void int_to_string(alt_string& target, std::size_t value)
@@ -233,24 +233,24 @@ TEST_CASE("alternative string type")
 
     SECTION("parse")
     {
-        auto doc = alt_json::parse("{\"foo\": \"bar\"}");
+        auto doc = alt_json::parse(R"({"foo": "bar"})");
         alt_string dump = doc.dump();
         CHECK(dump == R"({"foo":"bar"})");
     }
 
     SECTION("items")
     {
-        auto doc = alt_json::parse("{\"foo\": \"bar\"}");
+        auto doc = alt_json::parse(R"({"foo": "bar"})");
 
-        for ( auto item : doc.items() )
+        for (const auto& item : doc.items())
         {
-            CHECK( item.key() == "foo" );
-            CHECK( item.value() == "bar" );
+            CHECK(item.key() == "foo");
+            CHECK(item.value() == "bar");
         }
 
-        auto doc_array = alt_json::parse("[\"foo\", \"bar\"]");
+        auto doc_array = alt_json::parse(R"(["foo", "bar"])");
 
-        for ( auto item : doc_array.items() )
+        for (const auto& item : doc_array.items())
         {
             if (item.key() == "0" )
             {
@@ -258,11 +258,11 @@ TEST_CASE("alternative string type")
             }
             else if (item.key() == "1" )
             {
-                CHECK( item.value() == "bar" );
+                CHECK(item.value() == "bar");
             }
             else
             {
-                CHECK( false );
+                CHECK(false);
             }
         }
     }

test/src/unit-bson.cpp

@@ -101,7 +101,11 @@ TEST_CASE("BSON")
             { std::string("en\0try", 6), true }
         };
         CHECK_THROWS_AS(json::to_bson(j), json::out_of_range&);
+#if JSON_DIAGNOSTICS
+        CHECK_THROWS_WITH(json::to_bson(j), "[json.exception.out_of_range.409] (/en) BSON key cannot contain code point U+0000 (at byte 2)");
+#else
         CHECK_THROWS_WITH(json::to_bson(j), "[json.exception.out_of_range.409] BSON key cannot contain code point U+0000 (at byte 2)");
+#endif
     }
 
     SECTION("string length must be at least 1")
@@ -683,42 +687,42 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool boolean(bool)
+    bool boolean(bool /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_integer(json::number_integer_t)
+    bool number_integer(json::number_integer_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_unsigned(json::number_unsigned_t)
+    bool number_unsigned(json::number_unsigned_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_float(json::number_float_t, const std::string&)
+    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool string(std::string&)
+    bool string(std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool binary(std::vector<std::uint8_t>&)
+    bool binary(std::vector<std::uint8_t>& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool start_object(std::size_t)
+    bool start_object(std::size_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool key(std::string&)
+    bool key(std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
@@ -728,7 +732,7 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool start_array(std::size_t)
+    bool start_array(std::size_t /*unused*/)
     {
         return events_left-- > 0;
     }
@@ -738,7 +742,7 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool parse_error(std::size_t, const std::string&, const json::exception&)
+    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/) // NOLINT(readability-convert-member-functions-to-static)
     {
         return false;
     }
@@ -746,7 +750,7 @@ class SaxCountdown
   private:
     int events_left = 0;
 };
-}
+} // namespace
 
 TEST_CASE("Incomplete BSON Input")
 {
@@ -1235,7 +1239,11 @@ TEST_CASE("BSON numerical data")
                     };
 
                     CHECK_THROWS_AS(json::to_bson(j), json::out_of_range&);
+#if JSON_DIAGNOSTICS
+                    CHECK_THROWS_WITH_STD_STR(json::to_bson(j), "[json.exception.out_of_range.407] (/entry) integer number " + std::to_string(i) + " cannot be represented by BSON as it does not fit int64");
+#else
                     CHECK_THROWS_WITH_STD_STR(json::to_bson(j), "[json.exception.out_of_range.407] integer number " + std::to_string(i) + " cannot be represented by BSON as it does not fit int64");
+#endif
                 }
             }
 

test/src/unit-capacity.cpp

@@ -437,7 +437,7 @@ TEST_CASE("capacity")
         SECTION("boolean")
         {
             json j = true;
-            const json j_const(j);
+            const json j_const = true;
 
             SECTION("result of max_size")
             {
@@ -449,7 +449,7 @@ TEST_CASE("capacity")
         SECTION("string")
         {
             json j = "hello world";
-            const json j_const(j);
+            const json j_const = "hello world";
 
             SECTION("result of max_size")
             {
@@ -463,7 +463,7 @@ TEST_CASE("capacity")
             SECTION("empty array")
             {
                 json j = json::array();
-                const json j_const(j);
+                const json j_const = json::array();
 
                 SECTION("result of max_size")
                 {
@@ -475,7 +475,7 @@ TEST_CASE("capacity")
             SECTION("filled array")
             {
                 json j = {1, 2, 3};
-                const json j_const(j);
+                const json j_const = {1, 2, 3};
 
                 SECTION("result of max_size")
                 {
@@ -490,7 +490,7 @@ TEST_CASE("capacity")
             SECTION("empty object")
             {
                 json j = json::object();
-                const json j_const(j);
+                const json j_const = json::object();
 
                 SECTION("result of max_size")
                 {
@@ -502,7 +502,7 @@ TEST_CASE("capacity")
             SECTION("filled object")
             {
                 json j = {{"one", 1}, {"two", 2}, {"three", 3}};
-                const json j_const(j);
+                const json j_const = {{"one", 1}, {"two", 2}, {"three", 3}};
 
                 SECTION("result of max_size")
                 {
@@ -515,7 +515,7 @@ TEST_CASE("capacity")
         SECTION("number (integer)")
         {
             json j = -23;
-            const json j_const(j);
+            const json j_const = -23;
 
             SECTION("result of max_size")
             {
@@ -527,7 +527,7 @@ TEST_CASE("capacity")
         SECTION("number (unsigned)")
         {
             json j = 23u;
-            const json j_const(j);
+            const json j_const = 23u;
 
             SECTION("result of max_size")
             {
@@ -539,7 +539,7 @@ TEST_CASE("capacity")
         SECTION("number (float)")
         {
             json j = 23.42;
-            const json j_const(j);
+            const json j_const = 23.42;
 
             SECTION("result of max_size")
             {
@@ -551,7 +551,7 @@ TEST_CASE("capacity")
         SECTION("null")
         {
             json j = nullptr;
-            const json j_const(j);
+            const json j_const = nullptr;
 
             SECTION("result of max_size")
             {

test/src/unit-cbor.cpp

@@ -54,42 +54,42 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool boolean(bool)
+    bool boolean(bool /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_integer(json::number_integer_t)
+    bool number_integer(json::number_integer_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_unsigned(json::number_unsigned_t)
+    bool number_unsigned(json::number_unsigned_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_float(json::number_float_t, const std::string&)
+    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool string(std::string&)
+    bool string(std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool binary(std::vector<std::uint8_t>&)
+    bool binary(std::vector<std::uint8_t>& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool start_object(std::size_t)
+    bool start_object(std::size_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool key(std::string&)
+    bool key(std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
@@ -99,7 +99,7 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool start_array(std::size_t)
+    bool start_array(std::size_t /*unused*/)
     {
         return events_left-- > 0;
     }
@@ -109,7 +109,7 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool parse_error(std::size_t, const std::string&, const json::exception&)
+    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/) // NOLINT(readability-convert-member-functions-to-static)
     {
         return false;
     }
@@ -117,7 +117,7 @@ class SaxCountdown
   private:
     int events_left = 0;
 };
-}
+} // namespace
 
 TEST_CASE("CBOR")
 {
@@ -219,7 +219,7 @@ TEST_CASE("CBOR")
                         // create expected byte vector
                         std::vector<uint8_t> expected;
                         expected.push_back(static_cast<uint8_t>(0x3b));
-                        uint64_t positive = static_cast<uint64_t>(-1 - i);
+                        auto positive = static_cast<uint64_t>(-1 - i);
                         expected.push_back(static_cast<uint8_t>((positive >> 56) & 0xff));
                         expected.push_back(static_cast<uint8_t>((positive >> 48) & 0xff));
                         expected.push_back(static_cast<uint8_t>((positive >> 40) & 0xff));
@@ -276,7 +276,7 @@ TEST_CASE("CBOR")
                         // create expected byte vector
                         std::vector<uint8_t> expected;
                         expected.push_back(static_cast<uint8_t>(0x3a));
-                        uint32_t positive = static_cast<uint32_t>(static_cast<uint64_t>(-1 - i) & 0x00000000ffffffff);
+                        auto positive = static_cast<uint32_t>(static_cast<uint64_t>(-1 - i) & 0x00000000ffffffff);
                         expected.push_back(static_cast<uint8_t>((positive >> 24) & 0xff));
                         expected.push_back(static_cast<uint8_t>((positive >> 16) & 0xff));
                         expected.push_back(static_cast<uint8_t>((positive >> 8) & 0xff));
@@ -294,7 +294,7 @@ TEST_CASE("CBOR")
                                             (static_cast<uint32_t>(result[3]) << 010) +
                                             static_cast<uint32_t>(result[4]);
                         CHECK(restored == positive);
-                        CHECK(-1ll - restored == i);
+                        CHECK(-1LL - restored == i);
 
                         // roundtrip
                         CHECK(json::from_cbor(result) == j);
@@ -317,7 +317,7 @@ TEST_CASE("CBOR")
                         // create expected byte vector
                         std::vector<uint8_t> expected;
                         expected.push_back(static_cast<uint8_t>(0x39));
-                        uint16_t positive = static_cast<uint16_t>(-1 - i);
+                        auto positive = static_cast<uint16_t>(-1 - i);
                         expected.push_back(static_cast<uint8_t>((positive >> 8) & 0xff));
                         expected.push_back(static_cast<uint8_t>(positive & 0xff));
 
@@ -328,7 +328,7 @@ TEST_CASE("CBOR")
 
                         // check individual bytes
                         CHECK(result[0] == 0x39);
-                        uint16_t restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        auto restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
                         CHECK(restored == positive);
                         CHECK(-1 - restored == i);
 
@@ -346,7 +346,7 @@ TEST_CASE("CBOR")
                     const auto result = json::to_cbor(j);
                     CHECK(result == expected);
 
-                    int16_t restored = static_cast<int16_t>(-1 - ((result[1] << 8) + result[2]));
+                    auto restored = static_cast<int16_t>(-1 - ((result[1] << 8) + result[2]));
                     CHECK(restored == -9263);
 
                     // roundtrip
@@ -506,7 +506,7 @@ TEST_CASE("CBOR")
 
                         // check individual bytes
                         CHECK(result[0] == 0x19);
-                        uint16_t restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        auto restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
                         CHECK(restored == i);
 
                         // roundtrip
@@ -611,7 +611,7 @@ TEST_CASE("CBOR")
 
                 SECTION("-32768..-129 (int 16)")
                 {
-                    for (int16_t i = -32768; i <= -129; ++i)
+                    for (int16_t i = -32768; i <= int16_t(-129); ++i)
                     {
                         CAPTURE(i)
 
@@ -634,7 +634,7 @@ TEST_CASE("CBOR")
 
                         // check individual bytes
                         CHECK(result[0] == 0xd1);
-                        int16_t restored = static_cast<int16_t>((result[1] << 8) + result[2]);
+                        auto restored = static_cast<int16_t>((result[1] << 8) + result[2]);
                         CHECK(restored == i);
 
                         // roundtrip
@@ -699,7 +699,7 @@ TEST_CASE("CBOR")
 
                         // check individual bytes
                         CHECK(result[0] == 0x18);
-                        uint8_t restored = static_cast<uint8_t>(result[1]);
+                        auto restored = static_cast<uint8_t>(result[1]);
                         CHECK(restored == i);
 
                         // roundtrip
@@ -733,7 +733,7 @@ TEST_CASE("CBOR")
 
                         // check individual bytes
                         CHECK(result[0] == 0x19);
-                        uint16_t restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        auto restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
                         CHECK(restored == i);
 
                         // roundtrip
@@ -940,7 +940,7 @@ TEST_CASE("CBOR")
                 }
                 SECTION("-3.40282e+38(lowest float)")
                 {
-                    double v = static_cast<double>(std::numeric_limits<float>::lowest());
+                    auto v = static_cast<double>(std::numeric_limits<float>::lowest());
                     json j = v;
                     std::vector<uint8_t> expected =
                     {
@@ -1340,7 +1340,7 @@ TEST_CASE("CBOR")
 
             SECTION("{\"a\": {\"b\": {\"c\": {}}}}")
             {
-                json j = json::parse("{\"a\": {\"b\": {\"c\": {}}}}");
+                json j = json::parse(R"({"a": {"b": {"c": {}}}})");
                 std::vector<uint8_t> expected =
                 {
                     0xa1, 0x61, 0x61, 0xa1, 0x61, 0x62, 0xa1, 0x61, 0x63, 0xa0
@@ -2029,20 +2029,18 @@ TEST_CASE("CBOR roundtrips" * doctest::skip())
     SECTION("input from flynn")
     {
         // most of these are excluded due to differences in key order (not a real problem)
-        auto exclude_packed = std::set<std::string>
-        {
-            TEST_DATA_DIRECTORY "/json.org/1.json",
-            TEST_DATA_DIRECTORY "/json.org/2.json",
-            TEST_DATA_DIRECTORY "/json.org/3.json",
-            TEST_DATA_DIRECTORY "/json.org/4.json",
-            TEST_DATA_DIRECTORY "/json.org/5.json",
-            TEST_DATA_DIRECTORY "/json_testsuite/sample.json", // kills AppVeyor
-            TEST_DATA_DIRECTORY "/json_tests/pass1.json",
-            TEST_DATA_DIRECTORY "/regression/working_file.json",
-            TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object.json",
-            TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_duplicated_key.json",
-            TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_long_strings.json",
-        };
+        std::set<std::string> exclude_packed;
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json.org/1.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json.org/2.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json.org/3.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json.org/4.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json.org/5.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json_testsuite/sample.json"); // kills AppVeyor
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json_tests/pass1.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/regression/working_file.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_duplicated_key.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_long_strings.json");
 
         for (std::string filename :
                 {
@@ -2249,7 +2247,7 @@ TEST_CASE("CBOR roundtrips" * doctest::skip())
                 // parse CBOR file
                 auto packed = utils::read_binary_file(filename + ".cbor");
 
-                if (!exclude_packed.count(filename))
+                if (exclude_packed.count(filename) == 0u)
                 {
                     {
                         INFO_WITH_TEMP(filename + ": output adapters: std::vector<uint8_t>");
@@ -2323,7 +2321,7 @@ TEST_CASE("all CBOR first bytes")
             // check that parse_error.112 is only thrown if the
             // first byte is in the unsupported set
             INFO_WITH_TEMP(e.what());
-            if (std::find(unsupported.begin(), unsupported.end(), byte) != unsupported.end())
+            if (unsupported.find(byte) != unsupported.end())
             {
                 CHECK(e.id == 112);
             }

test/src/unit-class_lexer.cpp

@@ -36,19 +36,19 @@ using nlohmann::json;
 namespace
 {
 // shortcut to scan a string literal
-json::lexer::token_type scan_string(const char* s, const bool ignore_comments = false);
+json::lexer::token_type scan_string(const char* s, bool ignore_comments = false);
 json::lexer::token_type scan_string(const char* s, const bool ignore_comments)
 {
     auto ia = nlohmann::detail::input_adapter(s);
-    return nlohmann::detail::lexer<json, decltype(ia)>(std::move(ia), ignore_comments).scan();
-}
+    return nlohmann::detail::lexer<json, decltype(ia)>(std::move(ia), ignore_comments).scan(); // NOLINT(hicpp-move-const-arg,performance-move-const-arg)
 }
+} // namespace
 
-std::string get_error_message(const char* s, const bool ignore_comments = false);
+std::string get_error_message(const char* s, bool ignore_comments = false);
 std::string get_error_message(const char* s, const bool ignore_comments)
 {
     auto ia = nlohmann::detail::input_adapter(s);
-    auto lexer = nlohmann::detail::lexer<json, decltype(ia)>(std::move(ia), ignore_comments);
+    auto lexer = nlohmann::detail::lexer<json, decltype(ia)>(std::move(ia), ignore_comments); // NOLINT(hicpp-move-const-arg,performance-move-const-arg)
     lexer.scan();
     return lexer.get_error_message();
 }

test/src/unit-class_parser.cpp

@@ -42,13 +42,13 @@ class SaxEventLogger
   public:
     bool null()
     {
-        events.push_back("null()");
+        events.emplace_back("null()");
         return true;
     }
 
     bool boolean(bool val)
     {
-        events.push_back(val ? "boolean(true)" : "boolean(false)");
+        events.emplace_back(val ? "boolean(true)" : "boolean(false)");
         return true;
     }
 
@@ -64,7 +64,7 @@ class SaxEventLogger
         return true;
     }
 
-    bool number_float(json::number_float_t, const std::string& s)
+    bool number_float(json::number_float_t /*unused*/, const std::string& s)
     {
         events.push_back("number_float(" + s + ")");
         return true;
@@ -79,7 +79,7 @@ class SaxEventLogger
     bool binary(json::binary_t& val)
     {
         std::string binary_contents = "binary(";
-        std::string comma_space = "";
+        std::string comma_space;
         for (auto b : val)
         {
             binary_contents.append(comma_space);
@@ -95,7 +95,7 @@ class SaxEventLogger
     {
         if (elements == std::size_t(-1))
         {
-            events.push_back("start_object()");
+            events.emplace_back("start_object()");
         }
         else
         {
@@ -112,7 +112,7 @@ class SaxEventLogger
 
     bool end_object()
     {
-        events.push_back("end_object()");
+        events.emplace_back("end_object()");
         return true;
     }
 
@@ -120,7 +120,7 @@ class SaxEventLogger
     {
         if (elements == std::size_t(-1))
         {
-            events.push_back("start_array()");
+            events.emplace_back("start_array()");
         }
         else
         {
@@ -131,11 +131,11 @@ class SaxEventLogger
 
     bool end_array()
     {
-        events.push_back("end_array()");
+        events.emplace_back("end_array()");
         return true;
     }
 
-    bool parse_error(std::size_t position, const std::string&, const json::exception&)
+    bool parse_error(std::size_t position, const std::string& /*unused*/, const json::exception& /*unused*/)
     {
         errored = true;
         events.push_back("parse_error(" + std::to_string(position) + ")");
@@ -157,42 +157,42 @@ class SaxCountdown : public nlohmann::json::json_sax_t
         return events_left-- > 0;
     }
 
-    bool boolean(bool) override
+    bool boolean(bool /*val*/) override
     {
         return events_left-- > 0;
     }
 
-    bool number_integer(json::number_integer_t) override
+    bool number_integer(json::number_integer_t /*val*/) override
     {
         return events_left-- > 0;
     }
 
-    bool number_unsigned(json::number_unsigned_t) override
+    bool number_unsigned(json::number_unsigned_t /*val*/) override
     {
         return events_left-- > 0;
     }
 
-    bool number_float(json::number_float_t, const std::string&) override
+    bool number_float(json::number_float_t /*val*/, const std::string& /*s*/) override
     {
         return events_left-- > 0;
     }
 
-    bool string(std::string&) override
+    bool string(std::string& /*val*/) override
     {
         return events_left-- > 0;
     }
 
-    bool binary(json::binary_t&) override
+    bool binary(json::binary_t& /*val*/) override
     {
         return events_left-- > 0;
     }
 
-    bool start_object(std::size_t) override
+    bool start_object(std::size_t /*elements*/) override
     {
         return events_left-- > 0;
     }
 
-    bool key(std::string&) override
+    bool key(std::string& /*val*/) override
     {
         return events_left-- > 0;
     }
@@ -202,7 +202,7 @@ class SaxCountdown : public nlohmann::json::json_sax_t
         return events_left-- > 0;
     }
 
-    bool start_array(std::size_t) override
+    bool start_array(std::size_t /*elements*/) override
     {
         return events_left-- > 0;
     }
@@ -212,7 +212,7 @@ class SaxCountdown : public nlohmann::json::json_sax_t
         return events_left-- > 0;
     }
 
-    bool parse_error(std::size_t, const std::string&, const json::exception&) override
+    bool parse_error(std::size_t /*position*/, const std::string& /*last_token*/, const json::exception& /*ex*/) override
     {
         return false;
     }
@@ -267,7 +267,7 @@ bool accept_helper(const std::string& s)
     CHECK(json::parser(nlohmann::detail::input_adapter(s)).accept(false) == !el.errored);
 
     // 5. parse with simple callback
-    json::parser_callback_t cb = [](int, json::parse_event_t, json&)
+    json::parser_callback_t cb = [](int /*unused*/, json::parse_event_t /*unused*/, json& /*unused*/)
     {
         return true;
     };
@@ -395,7 +395,7 @@ TEST_CASE("parser class")
                 CHECK_THROWS_AS(parser_helper("\uFF01"), json::parse_error&);
                 CHECK_THROWS_AS(parser_helper("[-4:1,]"), json::parse_error&);
                 // unescaped control characters
-                CHECK_THROWS_AS(parser_helper("\"\x00\""), json::parse_error&);
+                CHECK_THROWS_AS(parser_helper("\"\x00\""), json::parse_error&); // NOLINT(bugprone-string-literal-with-embedded-nul)
                 CHECK_THROWS_AS(parser_helper("\"\x01\""), json::parse_error&);
                 CHECK_THROWS_AS(parser_helper("\"\x02\""), json::parse_error&);
                 CHECK_THROWS_AS(parser_helper("\"\x03\""), json::parse_error&);
@@ -427,7 +427,7 @@ TEST_CASE("parser class")
                 CHECK_THROWS_AS(parser_helper("\"\x1d\""), json::parse_error&);
                 CHECK_THROWS_AS(parser_helper("\"\x1e\""), json::parse_error&);
                 CHECK_THROWS_AS(parser_helper("\"\x1f\""), json::parse_error&);
-                CHECK_THROWS_WITH(parser_helper("\"\x00\""), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: missing closing quote; last read: '\"'");
+                CHECK_THROWS_WITH(parser_helper("\"\x00\""), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: missing closing quote; last read: '\"'"); // NOLINT(bugprone-string-literal-with-embedded-nul)
                 CHECK_THROWS_WITH(parser_helper("\"\x01\""), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: control character U+0001 (SOH) must be escaped to \\u0001; last read: '\"<U+0001>'");
                 CHECK_THROWS_WITH(parser_helper("\"\x02\""), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: control character U+0002 (STX) must be escaped to \\u0002; last read: '\"<U+0002>'");
                 CHECK_THROWS_WITH(parser_helper("\"\x03\""), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: control character U+0003 (ETX) must be escaped to \\u0003; last read: '\"<U+0003>'");
@@ -589,7 +589,7 @@ TEST_CASE("parser class")
 
                 SECTION("edge cases")
                 {
-                    // From RFC7159, Section 6:
+                    // From RFC8259, Section 6:
                     // Note that when such software is used, numbers that are
                     // integers and are in the range [-(2**53)+1, (2**53)-1]
                     // are interoperable in the sense that implementations will
@@ -603,7 +603,7 @@ TEST_CASE("parser class")
 
                 SECTION("over the edge cases")  // issue #178 - Integer conversion to unsigned (incorrect handling of 64 bit integers)
                 {
-                    // While RFC7159, Section 6 specifies a preference for support
+                    // While RFC8259, Section 6 specifies a preference for support
                     // for ranges in range of IEEE 754-2008 binary64 (double precision)
                     // this does not accommodate 64 bit integers without loss of accuracy.
                     // As 64 bit integers are now widely used in software, it is desirable
@@ -641,8 +641,8 @@ TEST_CASE("parser class")
             SECTION("overflow")
             {
                 // overflows during parsing yield an exception
-                CHECK_THROWS_AS(parser_helper("1.18973e+4932") == json(), json::out_of_range&);
-                CHECK_THROWS_WITH(parser_helper("1.18973e+4932") == json(),
+                CHECK_THROWS_AS(parser_helper("1.18973e+4932").empty(), json::out_of_range&);
+                CHECK_THROWS_WITH(parser_helper("1.18973e+4932").empty(),
                                   "[json.exception.out_of_range.406] number overflow parsing '1.18973e+4932'");
             }
 
@@ -770,7 +770,7 @@ TEST_CASE("parser class")
                 CHECK(accept_helper("\uFF01") == false);
                 CHECK(accept_helper("[-4:1,]") == false);
                 // unescaped control characters
-                CHECK(accept_helper("\"\x00\"") == false);
+                CHECK(accept_helper("\"\x00\"") == false); // NOLINT(bugprone-string-literal-with-embedded-nul)
                 CHECK(accept_helper("\"\x01\"") == false);
                 CHECK(accept_helper("\"\x02\"") == false);
                 CHECK(accept_helper("\"\x03\"") == false);
@@ -888,7 +888,7 @@ TEST_CASE("parser class")
 
                 SECTION("edge cases")
                 {
-                    // From RFC7159, Section 6:
+                    // From RFC8259, Section 6:
                     // Note that when such software is used, numbers that are
                     // integers and are in the range [-(2**53)+1, (2**53)-1]
                     // are interoperable in the sense that implementations will
@@ -902,7 +902,7 @@ TEST_CASE("parser class")
 
                 SECTION("over the edge cases")  // issue #178 - Integer conversion to unsigned (incorrect handling of 64 bit integers)
                 {
-                    // While RFC7159, Section 6 specifies a preference for support
+                    // While RFC8259, Section 6 specifies a preference for support
                     // for ranges in range of IEEE 754-2008 binary64 (double precision)
                     // this does not accommodate 64 bit integers without loss of accuracy.
                     // As 64 bit integers are now widely used in software, it is desirable
@@ -1155,7 +1155,7 @@ TEST_CASE("parser class")
                 case ('r'):
                 case ('t'):
                 {
-                    CHECK_NOTHROW(parser_helper(s.c_str()));
+                    CHECK_NOTHROW(parser_helper(s));
                     break;
                 }
 
@@ -1168,11 +1168,11 @@ TEST_CASE("parser class")
                 // any other combination of backslash and character is invalid
                 default:
                 {
-                    CHECK_THROWS_AS(parser_helper(s.c_str()), json::parse_error&);
+                    CHECK_THROWS_AS(parser_helper(s), json::parse_error&);
                     // only check error message if c is not a control character
                     if (c > 0x1f)
                     {
-                        CHECK_THROWS_WITH_STD_STR(parser_helper(s.c_str()),
+                        CHECK_THROWS_WITH_STD_STR(parser_helper(s),
                                                   "[json.exception.parse_error.101] parse error at line 1, column 3: syntax error while parsing value - invalid string: forbidden character after backslash; last read: '\"\\" + std::string(1, static_cast<char>(c)) + "'");
                     }
                     break;
@@ -1233,49 +1233,49 @@ TEST_CASE("parser class")
                 if (valid(c))
                 {
                     CAPTURE(s1)
-                    CHECK_NOTHROW(parser_helper(s1.c_str()));
+                    CHECK_NOTHROW(parser_helper(s1));
                     CAPTURE(s2)
-                    CHECK_NOTHROW(parser_helper(s2.c_str()));
+                    CHECK_NOTHROW(parser_helper(s2));
                     CAPTURE(s3)
-                    CHECK_NOTHROW(parser_helper(s3.c_str()));
+                    CHECK_NOTHROW(parser_helper(s3));
                     CAPTURE(s4)
-                    CHECK_NOTHROW(parser_helper(s4.c_str()));
+                    CHECK_NOTHROW(parser_helper(s4));
                 }
                 else
                 {
                     CAPTURE(s1)
-                    CHECK_THROWS_AS(parser_helper(s1.c_str()), json::parse_error&);
+                    CHECK_THROWS_AS(parser_helper(s1), json::parse_error&);
                     // only check error message if c is not a control character
                     if (c > 0x1f)
                     {
-                        CHECK_THROWS_WITH_STD_STR(parser_helper(s1.c_str()),
+                        CHECK_THROWS_WITH_STD_STR(parser_helper(s1),
                                                   "[json.exception.parse_error.101] parse error at line 1, column 7: syntax error while parsing value - invalid string: '\\u' must be followed by 4 hex digits; last read: '" + s1.substr(0, 7) + "'");
                     }
 
                     CAPTURE(s2)
-                    CHECK_THROWS_AS(parser_helper(s2.c_str()), json::parse_error&);
+                    CHECK_THROWS_AS(parser_helper(s2), json::parse_error&);
                     // only check error message if c is not a control character
                     if (c > 0x1f)
                     {
-                        CHECK_THROWS_WITH_STD_STR(parser_helper(s2.c_str()),
+                        CHECK_THROWS_WITH_STD_STR(parser_helper(s2),
                                                   "[json.exception.parse_error.101] parse error at line 1, column 6: syntax error while parsing value - invalid string: '\\u' must be followed by 4 hex digits; last read: '" + s2.substr(0, 6) + "'");
                     }
 
                     CAPTURE(s3)
-                    CHECK_THROWS_AS(parser_helper(s3.c_str()), json::parse_error&);
+                    CHECK_THROWS_AS(parser_helper(s3), json::parse_error&);
                     // only check error message if c is not a control character
                     if (c > 0x1f)
                     {
-                        CHECK_THROWS_WITH_STD_STR(parser_helper(s3.c_str()),
+                        CHECK_THROWS_WITH_STD_STR(parser_helper(s3),
                                                   "[json.exception.parse_error.101] parse error at line 1, column 5: syntax error while parsing value - invalid string: '\\u' must be followed by 4 hex digits; last read: '" + s3.substr(0, 5) + "'");
                     }
 
                     CAPTURE(s4)
-                    CHECK_THROWS_AS(parser_helper(s4.c_str()), json::parse_error&);
+                    CHECK_THROWS_AS(parser_helper(s4), json::parse_error&);
                     // only check error message if c is not a control character
                     if (c > 0x1f)
                     {
-                        CHECK_THROWS_WITH_STD_STR(parser_helper(s4.c_str()),
+                        CHECK_THROWS_WITH_STD_STR(parser_helper(s4),
                                                   "[json.exception.parse_error.101] parse error at line 1, column 4: syntax error while parsing value - invalid string: '\\u' must be followed by 4 hex digits; last read: '" + s4.substr(0, 4) + "'");
                     }
                 }
@@ -1381,7 +1381,7 @@ TEST_CASE("parser class")
                 case ('r'):
                 case ('t'):
                 {
-                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s.c_str()))).accept());
+                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s))).accept());
                     break;
                 }
 
@@ -1394,7 +1394,7 @@ TEST_CASE("parser class")
                 // any other combination of backslash and character is invalid
                 default:
                 {
-                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s.c_str()))).accept() == false);
+                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s))).accept() == false);
                     break;
                 }
             }
@@ -1453,27 +1453,27 @@ TEST_CASE("parser class")
                 if (valid(c))
                 {
                     CAPTURE(s1)
-                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s1.c_str()))).accept());
+                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s1))).accept());
                     CAPTURE(s2)
-                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s2.c_str()))).accept());
+                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s2))).accept());
                     CAPTURE(s3)
-                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s3.c_str()))).accept());
+                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s3))).accept());
                     CAPTURE(s4)
-                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s4.c_str()))).accept());
+                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s4))).accept());
                 }
                 else
                 {
                     CAPTURE(s1)
-                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s1.c_str()))).accept() == false);
+                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s1))).accept() == false);
 
                     CAPTURE(s2)
-                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s2.c_str()))).accept() == false);
+                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s2))).accept() == false);
 
                     CAPTURE(s3)
-                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s3.c_str()))).accept() == false);
+                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s3))).accept() == false);
 
                     CAPTURE(s4)
-                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s4.c_str()))).accept() == false);
+                    CHECK(json::parser(nlohmann::detail::input_adapter(std::string(s4))).accept() == false);
                 }
             }
         }
@@ -1499,16 +1499,9 @@ TEST_CASE("parser class")
 
         // test case to make sure the callback is properly evaluated after reading a key
         {
-            json::parser_callback_t cb = [](int, json::parse_event_t event, json&)
+            json::parser_callback_t cb = [](int /*unused*/, json::parse_event_t event, json& /*unused*/)
             {
-                if (event == json::parse_event_t::key)
-                {
-                    return false;
-                }
-                else
-                {
-                    return true;
-                }
+                return event != json::parse_event_t::key;
             };
 
             json x = json::parse("{\"key\": false}", cb);
@@ -1518,7 +1511,7 @@ TEST_CASE("parser class")
 
     SECTION("callback function")
     {
-        auto s_object = R"(
+        const auto* s_object = R"(
             {
                 "foo": 2,
                 "bar": {
@@ -1527,11 +1520,11 @@ TEST_CASE("parser class")
             }
         )";
 
-        auto s_array = R"(
+        const auto* s_array = R"(
             [1,2,[3,4,5],4,5]
         )";
 
-        auto structured_array = R"(
+        const auto* structured_array = R"(
             [
                 1,
                 {
@@ -1545,14 +1538,14 @@ TEST_CASE("parser class")
 
         SECTION("filter nothing")
         {
-            json j_object = json::parse(s_object, [](int, json::parse_event_t, const json&)
+            json j_object = json::parse(s_object, [](int /*unused*/, json::parse_event_t /*unused*/, const json& /*unused*/)
             {
                 return true;
             });
 
             CHECK (j_object == json({{"foo", 2}, {"bar", {{"baz", 1}}}}));
 
-            json j_array = json::parse(s_array, [](int, json::parse_event_t, const json&)
+            json j_array = json::parse(s_array, [](int /*unused*/, json::parse_event_t /*unused*/, const json& /*unused*/)
             {
                 return true;
             });
@@ -1562,7 +1555,7 @@ TEST_CASE("parser class")
 
         SECTION("filter everything")
         {
-            json j_object = json::parse(s_object, [](int, json::parse_event_t, const json&)
+            json j_object = json::parse(s_object, [](int /*unused*/, json::parse_event_t /*unused*/, const json& /*unused*/)
             {
                 return false;
             });
@@ -1570,7 +1563,7 @@ TEST_CASE("parser class")
             // the top-level object will be discarded, leaving a null
             CHECK (j_object.is_null());
 
-            json j_array = json::parse(s_array, [](int, json::parse_event_t, const json&)
+            json j_array = json::parse(s_array, [](int /*unused*/, json::parse_event_t /*unused*/, const json& /*unused*/)
             {
                 return false;
             });
@@ -1581,31 +1574,17 @@ TEST_CASE("parser class")
 
         SECTION("filter specific element")
         {
-            json j_object = json::parse(s_object, [](int, json::parse_event_t, const json & j)
+            json j_object = json::parse(s_object, [](int /*unused*/, json::parse_event_t /*unused*/, const json & j)
             {
                 // filter all number(2) elements
-                if (j == json(2))
-                {
-                    return false;
-                }
-                else
-                {
-                    return true;
-                }
+                return j != json(2);
             });
 
             CHECK (j_object == json({{"bar", {{"baz", 1}}}}));
 
-            json j_array = json::parse(s_array, [](int, json::parse_event_t, const json & j)
+            json j_array = json::parse(s_array, [](int /*unused*/, json::parse_event_t /*unused*/, const json & j)
             {
-                if (j == json(2))
-                {
-                    return false;
-                }
-                else
-                {
-                    return true;
-                }
+                return j != json(2);
             });
 
             CHECK (j_array == json({1, {3, 4, 5}, 4, 5}));
@@ -1613,32 +1592,18 @@ TEST_CASE("parser class")
 
         SECTION("filter object in array")
         {
-            json j_filtered1 = json::parse(structured_array, [](int, json::parse_event_t e, const json & parsed)
+            json j_filtered1 = json::parse(structured_array, [](int /*unused*/, json::parse_event_t e, const json & parsed)
             {
-                if (e == json::parse_event_t::object_end && parsed.contains("foo"))
-                {
-                    return false;
-                }
-                else
-                {
-                    return true;
-                }
+                return !(e == json::parse_event_t::object_end && parsed.contains("foo"));
             });
 
             // the specified object will be discarded, and removed.
             CHECK (j_filtered1.size() == 2);
             CHECK (j_filtered1 == json({1, {{"qux", "baz"}}}));
 
-            json j_filtered2 = json::parse(structured_array, [](int, json::parse_event_t e, const json& /*parsed*/)
+            json j_filtered2 = json::parse(structured_array, [](int /*unused*/, json::parse_event_t e, const json& /*parsed*/)
             {
-                if (e == json::parse_event_t::object_end)
-                {
-                    return false;
-                }
-                else
-                {
-                    return true;
-                }
+                return e != json::parse_event_t::object_end;
             });
 
             // removed all objects in array.
@@ -1651,7 +1616,7 @@ TEST_CASE("parser class")
             SECTION("first closing event")
             {
                 {
-                    json j_object = json::parse(s_object, [](int, json::parse_event_t e, const json&)
+                    json j_object = json::parse(s_object, [](int /*unused*/, json::parse_event_t e, const json& /*unused*/)
                     {
                         static bool first = true;
                         if (e == json::parse_event_t::object_end && first)
@@ -1659,10 +1624,8 @@ TEST_CASE("parser class")
                             first = false;
                             return false;
                         }
-                        else
-                        {
-                            return true;
-                        }
+
+                        return true;
                     });
 
                     // the first completed object will be discarded
@@ -1670,7 +1633,7 @@ TEST_CASE("parser class")
                 }
 
                 {
-                    json j_array = json::parse(s_array, [](int, json::parse_event_t e, const json&)
+                    json j_array = json::parse(s_array, [](int /*unused*/, json::parse_event_t e, const json& /*unused*/)
                     {
                         static bool first = true;
                         if (e == json::parse_event_t::array_end && first)
@@ -1678,10 +1641,8 @@ TEST_CASE("parser class")
                             first = false;
                             return false;
                         }
-                        else
-                        {
-                            return true;
-                        }
+
+                        return true;
                     });
 
                     // the first completed array will be discarded
@@ -1696,29 +1657,15 @@ TEST_CASE("parser class")
             // object and array is discarded only after the closing character
             // has been read
 
-            json j_empty_object = json::parse("{}", [](int, json::parse_event_t e, const json&)
+            json j_empty_object = json::parse("{}", [](int /*unused*/, json::parse_event_t e, const json& /*unused*/)
             {
-                if (e == json::parse_event_t::object_end)
-                {
-                    return false;
-                }
-                else
-                {
-                    return true;
-                }
+                return e != json::parse_event_t::object_end;
             });
             CHECK(j_empty_object == json());
 
-            json j_empty_array = json::parse("[]", [](int, json::parse_event_t e, const json&)
+            json j_empty_array = json::parse("[]", [](int /*unused*/, json::parse_event_t e, const json& /*unused*/)
             {
-                if (e == json::parse_event_t::array_end)
-                {
-                    return false;
-                }
-                else
-                {
-                    return true;
-                }
+                return e != json::parse_event_t::array_end;
             });
             CHECK(j_empty_array == json());
         }
@@ -1744,7 +1691,7 @@ TEST_CASE("parser class")
 
         SECTION("from array")
         {
-            uint8_t v[] = {'t', 'r', 'u', 'e'};
+            uint8_t v[] = {'t', 'r', 'u', 'e'}; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
             json j;
             json::parser(nlohmann::detail::input_adapter(std::begin(v), std::end(v))).parse(true, j);
             CHECK(j == json(true));
@@ -1784,7 +1731,7 @@ TEST_CASE("parser class")
     {
         SECTION("parser with callback")
         {
-            json::parser_callback_t cb = [](int, json::parse_event_t, json&)
+            json::parser_callback_t cb = [](int /*unused*/, json::parse_event_t /*unused*/, json& /*unused*/)
             {
                 return true;
             };

test/src/unit-comparison.cpp

@@ -41,7 +41,7 @@ bool f(A a, B b, U u = U())
 {
     return u(a, b);
 }
-}
+} // namespace
 
 TEST_CASE("lexicographical comparison operators")
 {
@@ -143,10 +143,10 @@ TEST_CASE("lexicographical comparison operators")
 
             // comparison with discarded elements
             json j_discarded(json::value_t::discarded);
-            for (size_t i = 0; i < j_values.size(); ++i)
+            for (const auto& v : j_values)
             {
-                CHECK( (j_values[i] == j_discarded) == false);
-                CHECK( (j_discarded == j_values[i]) == false);
+                CHECK( (v == j_discarded) == false);
+                CHECK( (j_discarded == v) == false);
                 CHECK( (j_discarded == j_discarded) == false);
             }
 

test/src/unit-constructor1.cpp

@@ -436,7 +436,7 @@ TEST_CASE("constructors")
 
         SECTION("char[]")
         {
-            char s[] {"Hello world"};
+            char s[] {"Hello world"}; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
             json j(s);
             CHECK(j.type() == json::value_t::string);
             CHECK(j == j_reference);
@@ -794,7 +794,7 @@ TEST_CASE("constructors")
 
         SECTION("integer literal with l suffix")
         {
-            json j(42l);
+            json j(42L);
             CHECK(j.type() == json::value_t::number_integer);
             CHECK(j == j_reference);
         }
@@ -808,7 +808,7 @@ TEST_CASE("constructors")
 
         SECTION("integer literal with ll suffix")
         {
-            json j(42ll);
+            json j(42LL);
             CHECK(j.type() == json::value_t::number_integer);
             CHECK(j == j_reference);
         }
@@ -892,7 +892,7 @@ TEST_CASE("constructors")
 
         SECTION("long double")
         {
-            long double n = 42.23l;
+            long double n = 42.23L;
             json j(n);
             CHECK(j.type() == json::value_t::number_float);
             CHECK(j.m_value.number_float == Approx(j_reference.m_value.number_float));
@@ -914,7 +914,7 @@ TEST_CASE("constructors")
 
         SECTION("integer literal with l suffix")
         {
-            json j(42.23l);
+            json j(42.23L);
             CHECK(j.type() == json::value_t::number_float);
             CHECK(j.m_value.number_float == Approx(j_reference.m_value.number_float));
         }
@@ -1115,84 +1115,113 @@ TEST_CASE("constructors")
         {
             SECTION("string")
             {
-                // This should break through any short string optimization in std::string
-                std::string source(1024, '!');
-                const char* source_addr = source.data();
-
                 SECTION("constructor with implicit types (array)")
                 {
+                    // This should break through any short string optimization in std::string
+                    std::string source(1024, '!');
+                    const auto* source_addr = source.data();
                     json j = {std::move(source)};
-                    CHECK(j[0].get_ref<std::string const&>().data() == source_addr);
+                    const auto* target_addr = j[0].get_ref<std::string const&>().data();
+                    const bool success = (target_addr == source_addr);
+                    CHECK(success);
                 }
 
                 SECTION("constructor with implicit types (object)")
                 {
+                    // This should break through any short string optimization in std::string
+                    std::string source(1024, '!');
+                    const auto* source_addr = source.data();
                     json j = {{"key", std::move(source)}};
-                    CHECK(j["key"].get_ref<std::string const&>().data() == source_addr);
+                    const auto* target_addr = j["key"].get_ref<std::string const&>().data();
+                    const bool success = (target_addr == source_addr);
+                    CHECK(success);
                 }
 
                 SECTION("constructor with implicit types (object key)")
                 {
+                    // This should break through any short string optimization in std::string
+                    std::string source(1024, '!');
+                    const auto* source_addr = source.data();
                     json j = {{std::move(source), 42}};
-                    CHECK(j.get_ref<json::object_t&>().begin()->first.data() == source_addr);
+                    const auto* target_addr = j.get_ref<json::object_t&>().begin()->first.data();
+                    const bool success = (target_addr == source_addr);
+                    CHECK(success);
                 }
             }
 
             SECTION("array")
             {
-                json::array_t source = {1, 2, 3};
-                const json* source_addr = source.data();
-
                 SECTION("constructor with implicit types (array)")
                 {
+                    json::array_t source = {1, 2, 3};
+                    const auto* source_addr = source.data();
                     json j {std::move(source)};
-                    CHECK(j[0].get_ref<json::array_t const&>().data() == source_addr);
+                    const auto* target_addr = j[0].get_ref<json::array_t const&>().data();
+                    const bool success = (target_addr == source_addr);
+                    CHECK(success);
                 }
 
                 SECTION("constructor with implicit types (object)")
                 {
+                    json::array_t source = {1, 2, 3};
+                    const auto* source_addr = source.data();
                     json j {{"key", std::move(source)}};
-                    CHECK(j["key"].get_ref<json::array_t const&>().data() == source_addr);
+                    const auto* target_addr = j["key"].get_ref<json::array_t const&>().data();
+                    const bool success = (target_addr == source_addr);
+                    CHECK(success);
                 }
 
                 SECTION("assignment with implicit types (array)")
                 {
+                    json::array_t source = {1, 2, 3};
+                    const auto* source_addr = source.data();
                     json j = {std::move(source)};
-                    CHECK(j[0].get_ref<json::array_t const&>().data() == source_addr);
+                    const auto* target_addr = j[0].get_ref<json::array_t const&>().data();
+                    const bool success = (target_addr == source_addr);
+                    CHECK(success);
                 }
 
                 SECTION("assignment with implicit types (object)")
                 {
+                    json::array_t source = {1, 2, 3};
+                    const auto* source_addr = source.data();
                     json j = {{"key", std::move(source)}};
-                    CHECK(j["key"].get_ref<json::array_t const&>().data() == source_addr);
+                    const auto* target_addr = j["key"].get_ref<json::array_t const&>().data();
+                    const bool success = (target_addr == source_addr);
+                    CHECK(success);
                 }
             }
 
             SECTION("object")
             {
-                json::object_t source = {{"hello", "world"}};
-                const json* source_addr = &source.at("hello");
-
                 SECTION("constructor with implicit types (array)")
                 {
+                    json::object_t source = {{"hello", "world"}};
+                    const json* source_addr = &source.at("hello");
                     json j {std::move(source)};
                     CHECK(&(j[0].get_ref<json::object_t const&>().at("hello")) == source_addr);
                 }
 
                 SECTION("constructor with implicit types (object)")
                 {
+                    json::object_t source = {{"hello", "world"}};
+                    const json* source_addr = &source.at("hello");
                     json j {{"key", std::move(source)}};
                     CHECK(&(j["key"].get_ref<json::object_t const&>().at("hello")) == source_addr);
                 }
 
                 SECTION("assignment with implicit types (array)")
                 {
+                    json::object_t source = {{"hello", "world"}};
+                    const json* source_addr = &source.at("hello");
                     json j = {std::move(source)};
                     CHECK(&(j[0].get_ref<json::object_t const&>().at("hello")) == source_addr);
                 }
 
                 SECTION("assignment with implicit types (object)")
                 {
+                    json::object_t source = {{"hello", "world"}};
+                    const json* source_addr = &source.at("hello");
                     json j = {{"key", std::move(source)}};
                     CHECK(&(j["key"].get_ref<json::object_t const&>().at("hello")) == source_addr);
                 }
@@ -1200,29 +1229,34 @@ TEST_CASE("constructors")
 
             SECTION("json")
             {
-                json source {1, 2, 3};
-                const json* source_addr = &source[0];
-
                 SECTION("constructor with implicit types (array)")
                 {
+                    json source {1, 2, 3};
+                    const json* source_addr = &source[0];
                     json j {std::move(source), {}};
                     CHECK(&j[0][0] == source_addr);
                 }
 
                 SECTION("constructor with implicit types (object)")
                 {
+                    json source {1, 2, 3};
+                    const json* source_addr = &source[0];
                     json j {{"key", std::move(source)}};
                     CHECK(&j["key"][0] == source_addr);
                 }
 
                 SECTION("assignment with implicit types (array)")
                 {
+                    json source {1, 2, 3};
+                    const json* source_addr = &source[0];
                     json j = {std::move(source), {}};
                     CHECK(&j[0][0] == source_addr);
                 }
 
                 SECTION("assignment with implicit types (object)")
                 {
+                    json source {1, 2, 3};
+                    const json* source_addr = &source[0];
                     json j = {{"key", std::move(source)}};
                     CHECK(&j["key"][0] == source_addr);
                 }

test/src/unit-constructor2.cpp

@@ -39,63 +39,63 @@ TEST_CASE("other constructors and destructor")
         SECTION("object")
         {
             json j {{"foo", 1}, {"bar", false}};
-            json k(j);
+            json k(j); // NOLINT(performance-unnecessary-copy-initialization)
             CHECK(j == k);
         }
 
         SECTION("array")
         {
             json j {"foo", 1, 42.23, false};
-            json k(j);
+            json k(j); // NOLINT(performance-unnecessary-copy-initialization)
             CHECK(j == k);
         }
 
         SECTION("null")
         {
             json j(nullptr);
-            json k(j);
+            json k(j); // NOLINT(performance-unnecessary-copy-initialization)
             CHECK(j == k);
         }
 
         SECTION("boolean")
         {
             json j(true);
-            json k(j);
+            json k(j); // NOLINT(performance-unnecessary-copy-initialization)
             CHECK(j == k);
         }
 
         SECTION("string")
         {
             json j("Hello world");
-            json k(j);
+            json k(j); // NOLINT(performance-unnecessary-copy-initialization)
             CHECK(j == k);
         }
 
         SECTION("number (integer)")
         {
             json j(42);
-            json k(j);
+            json k(j); // NOLINT(performance-unnecessary-copy-initialization)
             CHECK(j == k);
         }
 
         SECTION("number (unsigned)")
         {
             json j(42u);
-            json k(j);
+            json k(j); // NOLINT(performance-unnecessary-copy-initialization)
             CHECK(j == k);
         }
 
         SECTION("number (floating-point)")
         {
             json j(42.23);
-            json k(j);
+            json k(j); // NOLINT(performance-unnecessary-copy-initialization)
             CHECK(j == k);
         }
 
         SECTION("binary")
         {
             json j = json::binary({1, 2, 3});
-            json k(j);
+            json k(j); // NOLINT(performance-unnecessary-copy-initialization)
             CHECK(j == k);
         }
     }
@@ -106,7 +106,7 @@ TEST_CASE("other constructors and destructor")
         CHECK(j.type() == json::value_t::object);
         json k(std::move(j));
         CHECK(k.type() == json::value_t::object);
-        CHECK(j.type() == json::value_t::null);
+        CHECK(j.type() == json::value_t::null); // NOLINT: access after move is OK here
     }
 
     SECTION("copy assignment")
@@ -188,20 +188,20 @@ TEST_CASE("other constructors and destructor")
     {
         SECTION("object")
         {
-            auto j = new json {{"foo", 1}, {"bar", false}};
-            delete j;
+            auto* j = new json {{"foo", 1}, {"bar", false}}; // NOLINT(cppcoreguidelines-owning-memory)
+            delete j; // NOLINT(cppcoreguidelines-owning-memory)
         }
 
         SECTION("array")
         {
-            auto j = new json {"foo", 1, 1u, false, 23.42};
-            delete j;
+            auto* j = new json {"foo", 1, 1u, false, 23.42}; // NOLINT(cppcoreguidelines-owning-memory)
+            delete j; // NOLINT(cppcoreguidelines-owning-memory)
         }
 
         SECTION("string")
         {
-            auto j = new json("Hello world");
-            delete j;
+            auto* j = new json("Hello world"); // NOLINT(cppcoreguidelines-owning-memory)
+            delete j; // NOLINT(cppcoreguidelines-owning-memory)
         }
     }
 }

test/src/unit-convenience.cpp

@@ -37,7 +37,7 @@ using nlohmann::json;
 
 namespace
 {
-void check_escaped(const char* original, const char* escaped = "", const bool ensure_ascii = false);
+void check_escaped(const char* original, const char* escaped = "", bool ensure_ascii = false);
 void check_escaped(const char* original, const char* escaped, const bool ensure_ascii)
 {
     std::stringstream ss;
@@ -45,7 +45,7 @@ void check_escaped(const char* original, const char* escaped, const bool ensure_
     s.dump_escaped(original, ensure_ascii);
     CHECK(ss.str() == escaped);
 }
-}
+} // namespace
 
 TEST_CASE("convenience functions")
 {

test/src/unit-conversions.cpp

@@ -282,8 +282,8 @@ TEST_CASE("value conversion")
 
         SECTION("built-in arrays")
         {
-            const char str[] = "a string";
-            const int nbs[] = {0, 1, 2};
+            const char str[] = "a string"; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
+            const int nbs[] = {0, 1, 2}; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
 
             json j2 = nbs;
             json j3 = str;
@@ -387,8 +387,8 @@ TEST_CASE("value conversion")
 
         SECTION("built-in arrays")
         {
-            const int nbs[] = {0, 1, 2};
-            int nbs2[] = {0, 0, 0};
+            const int nbs[] = {0, 1, 2}; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
+            int nbs2[] = {0, 0, 0}; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
 
             json j2 = nbs;
             j2.get_to(nbs2);
@@ -633,7 +633,7 @@ TEST_CASE("value conversion")
 
         SECTION("boolean_t")
         {
-            json::boolean_t b = j.get<json::boolean_t>();
+            auto b = j.get<json::boolean_t>();
             CHECK(json(b) == j);
         }
 
@@ -726,25 +726,25 @@ TEST_CASE("value conversion")
 
         SECTION("number_integer_t")
         {
-            json::number_integer_t n = j.get<json::number_integer_t>();
+            auto n = j.get<json::number_integer_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("number_unsigned_t")
         {
-            json::number_unsigned_t n = j_unsigned.get<json::number_unsigned_t>();
+            auto n = j_unsigned.get<json::number_unsigned_t>();
             CHECK(json(n) == j_unsigned);
         }
 
         SECTION("short")
         {
-            short n = j.get<short>();
+            auto n = j.get<short>();
             CHECK(json(n) == j);
         }
 
         SECTION("unsigned short")
         {
-            unsigned short n = j.get<unsigned short>();
+            auto n = j.get<unsigned short>();
             CHECK(json(n) == j);
         }
 
@@ -756,7 +756,7 @@ TEST_CASE("value conversion")
 
         SECTION("unsigned int")
         {
-            unsigned int n = j.get<unsigned int>();
+            auto n = j.get<unsigned int>();
             CHECK(json(n) == j);
         }
 
@@ -768,163 +768,163 @@ TEST_CASE("value conversion")
 
         SECTION("unsigned long")
         {
-            unsigned long n = j.get<unsigned long>();
+            auto n = j.get<unsigned long>();
             CHECK(json(n) == j);
         }
 
         SECTION("long long")
         {
-            long long n = j.get<long long>();
+            auto n = j.get<long long>();
             CHECK(json(n) == j);
         }
 
         SECTION("unsigned long long")
         {
-            unsigned long long n = j.get<unsigned long long>();
+            auto n = j.get<unsigned long long>();
             CHECK(json(n) == j);
         }
 
         SECTION("int8_t")
         {
-            int8_t n = j.get<int8_t>();
+            auto n = j.get<int8_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("int16_t")
         {
-            int16_t n = j.get<int16_t>();
+            auto n = j.get<int16_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("int32_t")
         {
-            int32_t n = j.get<int32_t>();
+            auto n = j.get<int32_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("int64_t")
         {
-            int64_t n = j.get<int64_t>();
+            auto n = j.get<int64_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("int8_fast_t")
         {
-            int_fast8_t n = j.get<int_fast8_t>();
+            auto n = j.get<int_fast8_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("int16_fast_t")
         {
-            int_fast16_t n = j.get<int_fast16_t>();
+            auto n = j.get<int_fast16_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("int32_fast_t")
         {
-            int_fast32_t n = j.get<int_fast32_t>();
+            auto n = j.get<int_fast32_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("int64_fast_t")
         {
-            int_fast64_t n = j.get<int_fast64_t>();
+            auto n = j.get<int_fast64_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("int8_least_t")
         {
-            int_least8_t n = j.get<int_least8_t>();
+            auto n = j.get<int_least8_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("int16_least_t")
         {
-            int_least16_t n = j.get<int_least16_t>();
+            auto n = j.get<int_least16_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("int32_least_t")
         {
-            int_least32_t n = j.get<int_least32_t>();
+            auto n = j.get<int_least32_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("int64_least_t")
         {
-            int_least64_t n = j.get<int_least64_t>();
+            auto n = j.get<int_least64_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint8_t")
         {
-            uint8_t n = j.get<uint8_t>();
+            auto n = j.get<uint8_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint16_t")
         {
-            uint16_t n = j.get<uint16_t>();
+            auto n = j.get<uint16_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint32_t")
         {
-            uint32_t n = j.get<uint32_t>();
+            auto n = j.get<uint32_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint64_t")
         {
-            uint64_t n = j.get<uint64_t>();
+            auto n = j.get<uint64_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint8_fast_t")
         {
-            uint_fast8_t n = j.get<uint_fast8_t>();
+            auto n = j.get<uint_fast8_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint16_fast_t")
         {
-            uint_fast16_t n = j.get<uint_fast16_t>();
+            auto n = j.get<uint_fast16_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint32_fast_t")
         {
-            uint_fast32_t n = j.get<uint_fast32_t>();
+            auto n = j.get<uint_fast32_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint64_fast_t")
         {
-            uint_fast64_t n = j.get<uint_fast64_t>();
+            auto n = j.get<uint_fast64_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint8_least_t")
         {
-            uint_least8_t n = j.get<uint_least8_t>();
+            auto n = j.get<uint_least8_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint16_least_t")
         {
-            uint_least16_t n = j.get<uint_least16_t>();
+            auto n = j.get<uint_least16_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint32_least_t")
         {
-            uint_least32_t n = j.get<uint_least32_t>();
+            auto n = j.get<uint_least32_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("uint64_least_t")
         {
-            uint_least64_t n = j.get<uint_least64_t>();
+            auto n = j.get<uint_least64_t>();
             CHECK(json(n) == j);
         }
 
@@ -976,13 +976,13 @@ TEST_CASE("value conversion")
 
         SECTION("number_integer_t")
         {
-            json::number_integer_t n = j.get<json::number_integer_t>();
+            auto n = j.get<json::number_integer_t>();
             CHECK(json(n) == j);
         }
 
         SECTION("number_unsigned_t")
         {
-            json::number_unsigned_t n = j_unsigned.get<json::number_unsigned_t>();
+            auto n = j_unsigned.get<json::number_unsigned_t>();
             CHECK(json(n) == j_unsigned);
         }
 
@@ -1187,19 +1187,19 @@ TEST_CASE("value conversion")
 
         SECTION("number_float_t")
         {
-            json::number_float_t n = j.get<json::number_float_t>();
+            auto n = j.get<json::number_float_t>();
             CHECK(json(n).m_value.number_float == Approx(j.m_value.number_float));
         }
 
         SECTION("float")
         {
-            float n = j.get<float>();
+            auto n = j.get<float>();
             CHECK(json(n).m_value.number_float == Approx(j.m_value.number_float));
         }
 
         SECTION("double")
         {
-            double n = j.get<double>();
+            auto n = j.get<double>();
             CHECK(json(n).m_value.number_float == Approx(j.m_value.number_float));
         }
 
@@ -1639,6 +1639,7 @@ TEST_CASE("value conversion")
 
 enum class cards {kreuz, pik, herz, karo};
 
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays) - false positive
 NLOHMANN_JSON_SERIALIZE_ENUM(cards,
 {
     {cards::kreuz, "kreuz"},
@@ -1656,6 +1657,7 @@ enum TaskState
     TS_INVALID = -1,
 };
 
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays) - false positive
 NLOHMANN_JSON_SERIALIZE_ENUM(TaskState,
 {
     {TS_INVALID, nullptr},

test/src/unit-deserialization.cpp

@@ -42,13 +42,13 @@ struct SaxEventLogger : public nlohmann::json_sax<json>
 {
     bool null() override
     {
-        events.push_back("null()");
+        events.emplace_back("null()");
         return true;
     }
 
     bool boolean(bool val) override
     {
-        events.push_back(val ? "boolean(true)" : "boolean(false)");
+        events.emplace_back(val ? "boolean(true)" : "boolean(false)");
         return true;
     }
 
@@ -64,7 +64,7 @@ struct SaxEventLogger : public nlohmann::json_sax<json>
         return true;
     }
 
-    bool number_float(json::number_float_t, const std::string& s) override
+    bool number_float(json::number_float_t /*val*/, const std::string& s) override
     {
         events.push_back("number_float(" + s + ")");
         return true;
@@ -79,7 +79,7 @@ struct SaxEventLogger : public nlohmann::json_sax<json>
     bool binary(json::binary_t& val) override
     {
         std::string binary_contents = "binary(";
-        std::string comma_space = "";
+        std::string comma_space;
         for (auto b : val)
         {
             binary_contents.append(comma_space);
@@ -95,7 +95,7 @@ struct SaxEventLogger : public nlohmann::json_sax<json>
     {
         if (elements == std::size_t(-1))
         {
-            events.push_back("start_object()");
+            events.emplace_back("start_object()");
         }
         else
         {
@@ -112,7 +112,7 @@ struct SaxEventLogger : public nlohmann::json_sax<json>
 
     bool end_object() override
     {
-        events.push_back("end_object()");
+        events.emplace_back("end_object()");
         return true;
     }
 
@@ -120,7 +120,7 @@ struct SaxEventLogger : public nlohmann::json_sax<json>
     {
         if (elements == std::size_t(-1))
         {
-            events.push_back("start_array()");
+            events.emplace_back("start_array()");
         }
         else
         {
@@ -131,11 +131,11 @@ struct SaxEventLogger : public nlohmann::json_sax<json>
 
     bool end_array() override
     {
-        events.push_back("end_array()");
+        events.emplace_back("end_array()");
         return true;
     }
 
-    bool parse_error(std::size_t position, const std::string&, const json::exception&) override
+    bool parse_error(std::size_t position, const std::string& /*last_token*/, const json::exception& /*ex*/) override
     {
         events.push_back("parse_error(" + std::to_string(position) + ")");
         return false;
@@ -150,7 +150,7 @@ struct SaxEventLoggerExitAfterStartObject : public SaxEventLogger
     {
         if (elements == std::size_t(-1))
         {
-            events.push_back("start_object()");
+            events.emplace_back("start_object()");
         }
         else
         {
@@ -175,7 +175,7 @@ struct SaxEventLoggerExitAfterStartArray : public SaxEventLogger
     {
         if (elements == std::size_t(-1))
         {
-            events.push_back("start_array()");
+            events.emplace_back("start_array()");
         }
         else
         {
@@ -184,7 +184,7 @@ struct SaxEventLoggerExitAfterStartArray : public SaxEventLogger
         return false;
     }
 };
-}
+} // namespace
 
 TEST_CASE("deserialization")
 {
@@ -192,10 +192,12 @@ TEST_CASE("deserialization")
     {
         SECTION("stream")
         {
-            std::stringstream ss1, ss2, ss3;
-            ss1 << "[\"foo\",1,2,3,false,{\"one\":1}]";
-            ss2 << "[\"foo\",1,2,3,false,{\"one\":1}]";
-            ss3 << "[\"foo\",1,2,3,false,{\"one\":1}]";
+            std::stringstream ss1;
+            std::stringstream ss2;
+            std::stringstream ss3;
+            ss1 << R"(["foo",1,2,3,false,{"one":1}])";
+            ss2 << R"(["foo",1,2,3,false,{"one":1}])";
+            ss3 << R"(["foo",1,2,3,false,{"one":1}])";
             json j = json::parse(ss1);
             CHECK(json::accept(ss2));
             CHECK(j == json({"foo", 1, 2, 3, false, {{"one", 1}}}));
@@ -214,7 +216,7 @@ TEST_CASE("deserialization")
 
         SECTION("string literal")
         {
-            auto s = "[\"foo\",1,2,3,false,{\"one\":1}]";
+            const auto* s = R"(["foo",1,2,3,false,{"one":1}])";
             json j = json::parse(s);
             CHECK(json::accept(s));
             CHECK(j == json({"foo", 1, 2, 3, false, {{"one", 1}}}));
@@ -233,7 +235,7 @@ TEST_CASE("deserialization")
 
         SECTION("string_t")
         {
-            json::string_t s = "[\"foo\",1,2,3,false,{\"one\":1}]";
+            json::string_t s = R"(["foo",1,2,3,false,{"one":1}])";
             json j = json::parse(s);
             CHECK(json::accept(s));
             CHECK(j == json({"foo", 1, 2, 3, false, {{"one", 1}}}));
@@ -253,7 +255,7 @@ TEST_CASE("deserialization")
         SECTION("operator<<")
         {
             std::stringstream ss;
-            ss << "[\"foo\",1,2,3,false,{\"one\":1}]";
+            ss << R"(["foo",1,2,3,false,{"one":1}])";
             json j;
             j << ss;
             CHECK(j == json({"foo", 1, 2, 3, false, {{"one", 1}}}));
@@ -262,7 +264,7 @@ TEST_CASE("deserialization")
         SECTION("operator>>")
         {
             std::stringstream ss;
-            ss << "[\"foo\",1,2,3,false,{\"one\":1}]";
+            ss << R"(["foo",1,2,3,false,{"one":1}])";
             json j;
             ss >> j;
             CHECK(j == json({"foo", 1, 2, 3, false, {{"one", 1}}}));
@@ -278,12 +280,16 @@ TEST_CASE("deserialization")
     {
         SECTION("stream")
         {
-            std::stringstream ss1, ss2, ss3, ss4, ss5;
-            ss1 << "[\"foo\",1,2,3,false,{\"one\":1}";
-            ss2 << "[\"foo\",1,2,3,false,{\"one\":1}";
-            ss3 << "[\"foo\",1,2,3,false,{\"one\":1}";
-            ss4 << "[\"foo\",1,2,3,false,{\"one\":1}";
-            ss5 << "[\"foo\",1,2,3,false,{\"one\":1}";
+            std::stringstream ss1;
+            std::stringstream ss2;
+            std::stringstream ss3;
+            std::stringstream ss4;
+            std::stringstream ss5;
+            ss1 << R"(["foo",1,2,3,false,{"one":1})";
+            ss2 << R"(["foo",1,2,3,false,{"one":1})";
+            ss3 << R"(["foo",1,2,3,false,{"one":1})";
+            ss4 << R"(["foo",1,2,3,false,{"one":1})";
+            ss5 << R"(["foo",1,2,3,false,{"one":1})";
 
             json _;
             CHECK_THROWS_AS(_ = json::parse(ss1), json::parse_error&);
@@ -309,7 +315,7 @@ TEST_CASE("deserialization")
 
         SECTION("string")
         {
-            json::string_t s = "[\"foo\",1,2,3,false,{\"one\":1}";
+            json::string_t s = R"(["foo",1,2,3,false,{"one":1})";
             json _;
             CHECK_THROWS_AS(_ = json::parse(s), json::parse_error&);
             CHECK_THROWS_WITH(_ = json::parse(s),
@@ -334,9 +340,10 @@ TEST_CASE("deserialization")
 
         SECTION("operator<<")
         {
-            std::stringstream ss1, ss2;
-            ss1 << "[\"foo\",1,2,3,false,{\"one\":1}";
-            ss2 << "[\"foo\",1,2,3,false,{\"one\":1}";
+            std::stringstream ss1;
+            std::stringstream ss2;
+            ss1 << R"(["foo",1,2,3,false,{"one":1})";
+            ss2 << R"(["foo",1,2,3,false,{"one":1})";
             json j;
             CHECK_THROWS_AS(j << ss1, json::parse_error&);
             CHECK_THROWS_WITH(j << ss2,
@@ -345,9 +352,10 @@ TEST_CASE("deserialization")
 
         SECTION("operator>>")
         {
-            std::stringstream ss1, ss2;
-            ss1 << "[\"foo\",1,2,3,false,{\"one\":1}";
-            ss2 << "[\"foo\",1,2,3,false,{\"one\":1}";
+            std::stringstream ss1;
+            std::stringstream ss2;
+            ss1 << R"(["foo",1,2,3,false,{"one":1})";
+            ss2 << R"(["foo",1,2,3,false,{"one":1})";
             json j;
             CHECK_THROWS_AS(ss1 >> j, json::parse_error&);
             CHECK_THROWS_WITH(ss2 >> j,
@@ -392,7 +400,7 @@ TEST_CASE("deserialization")
 
             SECTION("from array")
             {
-                uint8_t v[] = {'t', 'r', 'u', 'e'};
+                uint8_t v[] = {'t', 'r', 'u', 'e'}; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
                 CHECK(json::parse(v) == json(true));
                 CHECK(json::accept(v));
 
@@ -404,7 +412,7 @@ TEST_CASE("deserialization")
 
             SECTION("from chars")
             {
-                uint8_t* v = new uint8_t[5];
+                auto* v = new uint8_t[5]; // NOLINT(cppcoreguidelines-owning-memory)
                 v[0] = 't';
                 v[1] = 'r';
                 v[2] = 'u';
@@ -418,7 +426,7 @@ TEST_CASE("deserialization")
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"boolean(true)"}));
 
-                delete[] v;
+                delete[] v; // NOLINT(cppcoreguidelines-owning-memory)
             }
 
             SECTION("from std::string")
@@ -488,7 +496,7 @@ TEST_CASE("deserialization")
 
             SECTION("from array")
             {
-                uint8_t v[] = {'t', 'r', 'u', 'e'};
+                uint8_t v[] = {'t', 'r', 'u', 'e'}; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
                 CHECK(json::parse(std::begin(v), std::end(v)) == json(true));
                 CHECK(json::accept(std::begin(v), std::end(v)));
 
@@ -553,7 +561,7 @@ TEST_CASE("deserialization")
         {
             SECTION("case 1")
             {
-                uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u'};
+                std::array<std::uint8_t, 9> v = {{'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u'}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -570,7 +578,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 2")
             {
-                uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u', '1'};
+                std::array<std::uint8_t, 10> v = {{'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u', '1'}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -587,7 +595,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 3")
             {
-                uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u', '1', '1', '1', '1', '1', '1', '1', '1'};
+                std::array<std::uint8_t, 17> v = {{'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u', '1', '1', '1', '1', '1', '1', '1', '1'}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -604,7 +612,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 4")
             {
-                uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', 'u', '1', '1', '1', '1', '1', '1', '1', '1', '\\'};
+                std::array<std::uint8_t, 17> v = {{'\"', 'a', 'a', 'a', 'a', 'a', 'a', 'u', '1', '1', '1', '1', '1', '1', '1', '1', '\\'}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -621,7 +629,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 5")
             {
-                uint8_t v[] = {'\"', 0x7F, 0xC1};
+                std::array<std::uint8_t, 3> v = {{'\"', 0x7F, 0xC1}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -638,7 +646,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 6")
             {
-                uint8_t v[] = {'\"', 0x7F, 0xDF, 0x7F};
+                std::array<std::uint8_t, 4> v = {{'\"', 0x7F, 0xDF, 0x7F}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK_THROWS_WITH(_ = json::parse(std::begin(v), std::end(v)),
@@ -657,7 +665,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 7")
             {
-                uint8_t v[] = {'\"', 0x7F, 0xDF, 0xC0};
+                std::array<std::uint8_t, 4> v = {{'\"', 0x7F, 0xDF, 0xC0}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -674,7 +682,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 8")
             {
-                uint8_t v[] = {'\"', 0x7F, 0xE0, 0x9F};
+                std::array<std::uint8_t, 4> v = {{'\"', 0x7F, 0xE0, 0x9F}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -691,7 +699,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 9")
             {
-                uint8_t v[] = {'\"', 0x7F, 0xEF, 0xC0};
+                std::array<std::uint8_t, 4> v = {{'\"', 0x7F, 0xEF, 0xC0}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -708,7 +716,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 10")
             {
-                uint8_t v[] = {'\"', 0x7F, 0xED, 0x7F};
+                std::array<std::uint8_t, 4> v = {{'\"', 0x7F, 0xED, 0x7F}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -725,7 +733,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 11")
             {
-                uint8_t v[] = {'\"', 0x7F, 0xF0, 0x8F};
+                std::array<std::uint8_t, 4> v = {{'\"', 0x7F, 0xF0, 0x8F}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -742,7 +750,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 12")
             {
-                uint8_t v[] = {'\"', 0x7F, 0xF0, 0xC0};
+                std::array<std::uint8_t, 4> v = {{'\"', 0x7F, 0xF0, 0xC0}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -759,7 +767,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 13")
             {
-                uint8_t v[] = {'\"', 0x7F, 0xF3, 0x7F};
+                std::array<std::uint8_t, 4> v = {{'\"', 0x7F, 0xF3, 0x7F}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -776,7 +784,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 14")
             {
-                uint8_t v[] = {'\"', 0x7F, 0xF3, 0xC0};
+                std::array<std::uint8_t, 4> v = {{'\"', 0x7F, 0xF3, 0xC0}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -793,7 +801,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 15")
             {
-                uint8_t v[] = {'\"', 0x7F, 0xF4, 0x7F};
+                std::array<std::uint8_t, 4> v = {{'\"', 0x7F, 0xF4, 0x7F}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -810,7 +818,7 @@ TEST_CASE("deserialization")
 
             SECTION("case 16")
             {
-                uint8_t v[] = {'{', '\"', '\"', ':', '1', '1'};
+                std::array<std::uint8_t, 6> v = {{'{', '\"', '\"', ':', '1', '1'}};
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK(!json::accept(std::begin(v), std::end(v)));
@@ -860,7 +868,8 @@ TEST_CASE("deserialization")
             CHECK(json::parse(bom + "1") == 1);
             CHECK(json::parse(std::istringstream(bom + "1")) == 1);
 
-            SaxEventLogger l1, l2;
+            SaxEventLogger l1;
+            SaxEventLogger l2;
             CHECK(json::sax_parse(std::istringstream(bom + "1"), &l1));
             CHECK(json::sax_parse(bom + "1", &l2));
             CHECK(l1.events.size() == 1);
@@ -886,7 +895,8 @@ TEST_CASE("deserialization")
             CHECK_THROWS_WITH(_ = json::parse(std::istringstream(bom.substr(0, 2))),
                               "[json.exception.parse_error.101] parse error at line 1, column 3: syntax error while parsing value - invalid BOM; must be 0xEF 0xBB 0xBF if given; last read: '\xEF\xBB'");
 
-            SaxEventLogger l1, l2;
+            SaxEventLogger l1;
+            SaxEventLogger l2;
             CHECK(!json::sax_parse(std::istringstream(bom.substr(0, 2)), &l1));
             CHECK(!json::sax_parse(bom.substr(0, 2), &l2));
             CHECK(l1.events.size() == 1);
@@ -912,7 +922,8 @@ TEST_CASE("deserialization")
             CHECK_THROWS_WITH(_ = json::parse(std::istringstream(bom.substr(0, 1))),
                               "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid BOM; must be 0xEF 0xBB 0xBF if given; last read: '\xEF'");
 
-            SaxEventLogger l1, l2;
+            SaxEventLogger l1;
+            SaxEventLogger l2;
             CHECK(!json::sax_parse(std::istringstream(bom.substr(0, 1)), &l1));
             CHECK(!json::sax_parse(bom.substr(0, 1), &l2));
             CHECK(l1.events.size() == 1);
@@ -942,7 +953,7 @@ TEST_CASE("deserialization")
                         CAPTURE(i1)
                         CAPTURE(i2)
 
-                        std::string s = "";
+                        std::string s;
                         s.push_back(static_cast<char>(bom[0] + i0));
                         s.push_back(static_cast<char>(bom[1] + i1));
                         s.push_back(static_cast<char>(bom[2] + i2));
@@ -1012,7 +1023,7 @@ TEST_CASE("deserialization")
 
     SECTION("SAX and early abort")
     {
-        std::string s = "[1, [\"string\", 43.12], null, {\"key1\": true, \"key2\": false}]";
+        std::string s = R"([1, ["string", 43.12], null, {"key1": true, "key2": false}])";
 
         SaxEventLogger default_logger;
         SaxEventLoggerExitAfterStartObject exit_after_start_object;

test/src/unit-diagnostics.cpp

@@ -0,0 +1,177 @@
+/*
+    __ _____ _____ _____
+ __|  |   __|     |   | |  JSON for Modern C++ (test suite)
+|  |  |__   |  |  | | | |  version 3.9.1
+|_____|_____|_____|_|___|  https://github.com/nlohmann/json
+
+Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+SPDX-License-Identifier: MIT
+Copyright (c) 2013-2019 Niels Lohmann <http://nlohmann.me>.
+
+Permission is hereby  granted, free of charge, to any  person obtaining a copy
+of this software and associated  documentation files (the "Software"), to deal
+in the Software  without restriction, including without  limitation the rights
+to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
+copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
+IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
+FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
+AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
+LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "doctest_compatibility.h"
+
+#ifdef JSON_DIAGNOSTICS
+    #undef JSON_DIAGNOSTICS
+#endif
+
+#define JSON_DIAGNOSTICS 1
+
+#include <nlohmann/json.hpp>
+using nlohmann::json;
+
+TEST_CASE("Better diagnostics")
+{
+    SECTION("empty JSON Pointer")
+    {
+        json j = 1;
+        std::string s;
+        CHECK_THROWS_WITH_AS(s = j.get<std::string>(), "[json.exception.type_error.302] type must be string, but is number", json::type_error);
+    }
+
+    SECTION("invalid type")
+    {
+        json j;
+        j["a"]["b"]["c"] = 1;
+        std::string s;
+        CHECK_THROWS_WITH_AS(s = j["a"]["b"]["c"].get<std::string>(), "[json.exception.type_error.302] (/a/b/c) type must be string, but is number", json::type_error);
+    }
+
+    SECTION("missing key")
+    {
+        json j;
+        j["object"]["object"] = true;
+        CHECK_THROWS_WITH_AS(j["object"].at("not_found"), "[json.exception.out_of_range.403] (/object) key 'not_found' not found", json::out_of_range);
+    }
+
+    SECTION("array index out of range")
+    {
+        json j;
+        j["array"][4] = true;
+        CHECK_THROWS_WITH_AS(j["array"].at(5), "[json.exception.out_of_range.401] (/array) array index 5 is out of range", json::out_of_range);
+    }
+
+    SECTION("array index at wrong type")
+    {
+        json j;
+        j["array"][4] = true;
+        CHECK_THROWS_WITH_AS(j["array"][4][5], "[json.exception.type_error.305] (/array/4) cannot use operator[] with a numeric argument with boolean", json::type_error);
+    }
+
+    SECTION("wrong iterator")
+    {
+        json j;
+        j["array"] = json::array();
+        CHECK_THROWS_WITH_AS(j["array"].erase(j.begin()), "[json.exception.invalid_iterator.202] (/array) iterator does not fit current value", json::invalid_iterator);
+    }
+
+    SECTION("JSON Pointer escaping")
+    {
+        json j;
+        j["a/b"]["m~n"] = 1;
+        std::string s;
+        CHECK_THROWS_WITH_AS(s = j["a/b"]["m~n"].get<std::string>(), "[json.exception.type_error.302] (/a~1b/m~0n) type must be string, but is number", json::type_error);
+    }
+
+    SECTION("Parse error")
+    {
+        json _;
+        CHECK_THROWS_WITH_AS(_ = json::parse(""), "[json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error);
+    }
+
+    SECTION("Regression test for https://github.com/nlohmann/json/pull/2562#pullrequestreview-574858448")
+    {
+        CHECK_THROWS_WITH_AS(json({"0", "0"})[1].get<int>(), "[json.exception.type_error.302] (/1) type must be number, but is string", json::type_error);
+        CHECK_THROWS_WITH_AS(json({"0", "1"})[1].get<int>(), "[json.exception.type_error.302] (/1) type must be number, but is string", json::type_error);
+    }
+
+    SECTION("Regression test for https://github.com/nlohmann/json/pull/2562/files/380a613f2b5d32425021129cd1f371ddcfd54ddf#r563259793")
+    {
+        json j;
+        j["/foo"] = {1, 2, 3};
+        CHECK_THROWS_WITH_AS(j.unflatten(), "[json.exception.type_error.315] (/~1foo) values in object must be primitive", json::type_error);
+    }
+
+    SECTION("Regression test for https://github.com/nlohmann/json/issues/2838")
+    {
+        // void push_back(basic_json&& val)
+        {
+            json j_arr = json::array();
+            j_arr.push_back(json::object());
+            j_arr.push_back(json::object());
+            j_arr.push_back(json::object());
+            j_arr.push_back(json::object());
+            json j_obj = json::object();
+            j_obj["key"] = j_arr;
+        }
+
+        // void push_back(const basic_json& val)
+        {
+            json j_arr = json::array();
+            auto object = json::object();
+            j_arr.push_back(object);
+            j_arr.push_back(object);
+            j_arr.push_back(object);
+            j_arr.push_back(object);
+            json j_obj = json::object();
+            j_obj["key"] = j_arr;
+        }
+
+        // reference emplace_back(Args&& ... args)
+        {
+            json j_arr = json::array();
+            j_arr.emplace_back(json::object());
+            j_arr.emplace_back(json::object());
+            j_arr.emplace_back(json::object());
+            j_arr.emplace_back(json::object());
+            json j_obj = json::object();
+            j_obj["key"] = j_arr;
+        }
+
+        // iterator insert(const_iterator pos, const basic_json& val)
+        {
+            json j_arr = json::array();
+            j_arr.insert(j_arr.begin(), json::object());
+            j_arr.insert(j_arr.begin(), json::object());
+            j_arr.insert(j_arr.begin(), json::object());
+            j_arr.insert(j_arr.begin(), json::object());
+            json j_obj = json::object();
+            j_obj["key"] = j_arr;
+        }
+
+        // iterator insert(const_iterator pos, size_type cnt, const basic_json& val)
+        {
+            json j_arr = json::array();
+            j_arr.insert(j_arr.begin(), 2, json::object());
+            json j_obj = json::object();
+            j_obj["key"] = j_arr;
+        }
+
+        // iterator insert(const_iterator pos, const_iterator first, const_iterator last)
+        {
+            json j_arr = json::array();
+            json j_objects = {json::object(), json::object()};
+            j_arr.insert(j_arr.begin(), j_objects.begin(), j_objects.end());
+            json j_obj = json::object();
+            j_obj["key"] = j_arr;
+        }
+    }
+}

test/src/unit-element_access2.cpp

@@ -202,7 +202,7 @@ TEST_CASE("element access 2")
                     SECTION("null")
                     {
                         json j_nonobject(json::value_t::null);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::null);
                         CHECK_THROWS_AS(j_nonobject.value("foo", 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("foo", 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("foo", 1),
@@ -214,7 +214,7 @@ TEST_CASE("element access 2")
                     SECTION("boolean")
                     {
                         json j_nonobject(json::value_t::boolean);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::boolean);
                         CHECK_THROWS_AS(j_nonobject.value("foo", 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("foo", 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("foo", 1),
@@ -226,7 +226,7 @@ TEST_CASE("element access 2")
                     SECTION("string")
                     {
                         json j_nonobject(json::value_t::string);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::string);
                         CHECK_THROWS_AS(j_nonobject.value("foo", 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("foo", 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("foo", 1),
@@ -238,7 +238,7 @@ TEST_CASE("element access 2")
                     SECTION("array")
                     {
                         json j_nonobject(json::value_t::array);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::array);
                         CHECK_THROWS_AS(j_nonobject.value("foo", 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("foo", 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("foo", 1),
@@ -250,7 +250,7 @@ TEST_CASE("element access 2")
                     SECTION("number (integer)")
                     {
                         json j_nonobject(json::value_t::number_integer);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::number_integer);
                         CHECK_THROWS_AS(j_nonobject.value("foo", 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("foo", 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("foo", 1),
@@ -262,7 +262,7 @@ TEST_CASE("element access 2")
                     SECTION("number (unsigned)")
                     {
                         json j_nonobject(json::value_t::number_unsigned);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::number_unsigned);
                         CHECK_THROWS_AS(j_nonobject.value("foo", 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("foo", 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("foo", 1),
@@ -274,7 +274,7 @@ TEST_CASE("element access 2")
                     SECTION("number (floating-point)")
                     {
                         json j_nonobject(json::value_t::number_float);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::number_float);
                         CHECK_THROWS_AS(j_nonobject.value("foo", 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("foo", 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("foo", 1),
@@ -320,7 +320,7 @@ TEST_CASE("element access 2")
                     SECTION("null")
                     {
                         json j_nonobject(json::value_t::null);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::null);
                         CHECK_THROWS_AS(j_nonobject.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("/foo"_json_pointer, 1),
@@ -332,7 +332,7 @@ TEST_CASE("element access 2")
                     SECTION("boolean")
                     {
                         json j_nonobject(json::value_t::boolean);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::boolean);
                         CHECK_THROWS_AS(j_nonobject.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("/foo"_json_pointer, 1),
@@ -344,7 +344,7 @@ TEST_CASE("element access 2")
                     SECTION("string")
                     {
                         json j_nonobject(json::value_t::string);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::string);
                         CHECK_THROWS_AS(j_nonobject.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("/foo"_json_pointer, 1),
@@ -356,7 +356,7 @@ TEST_CASE("element access 2")
                     SECTION("array")
                     {
                         json j_nonobject(json::value_t::array);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::array);
                         CHECK_THROWS_AS(j_nonobject.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("/foo"_json_pointer, 1),
@@ -368,7 +368,7 @@ TEST_CASE("element access 2")
                     SECTION("number (integer)")
                     {
                         json j_nonobject(json::value_t::number_integer);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::number_integer);
                         CHECK_THROWS_AS(j_nonobject.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("/foo"_json_pointer, 1),
@@ -380,7 +380,7 @@ TEST_CASE("element access 2")
                     SECTION("number (unsigned)")
                     {
                         json j_nonobject(json::value_t::number_unsigned);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::number_unsigned);
                         CHECK_THROWS_AS(j_nonobject.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("/foo"_json_pointer, 1),
@@ -392,7 +392,7 @@ TEST_CASE("element access 2")
                     SECTION("number (floating-point)")
                     {
                         json j_nonobject(json::value_t::number_float);
-                        const json j_nonobject_const(j_nonobject);
+                        const json j_nonobject_const(json::value_t::number_float);
                         CHECK_THROWS_AS(j_nonobject.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_AS(j_nonobject_const.value("/foo"_json_pointer, 1), json::type_error&);
                         CHECK_THROWS_WITH(j_nonobject.value("/foo"_json_pointer, 1),
@@ -811,7 +811,7 @@ TEST_CASE("element access 2")
         {
             SECTION("existing element")
             {
-                for (auto key :
+                for (const auto* key :
                         {"integer", "unsigned", "floating", "null", "string", "boolean", "object", "array"
                         })
                 {
@@ -900,7 +900,7 @@ TEST_CASE("element access 2")
         {
             SECTION("existing element")
             {
-                for (auto key :
+                for (const auto* key :
                         {"integer", "unsigned", "floating", "null", "string", "boolean", "object", "array"
                         })
                 {
@@ -920,7 +920,7 @@ TEST_CASE("element access 2")
                 SECTION("null")
                 {
                     json j_nonobject(json::value_t::null);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::null);
                     CHECK(j_nonobject.count("foo") == 0);
                     CHECK(j_nonobject_const.count("foo") == 0);
                 }
@@ -928,7 +928,7 @@ TEST_CASE("element access 2")
                 SECTION("string")
                 {
                     json j_nonobject(json::value_t::string);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::string);
                     CHECK(j_nonobject.count("foo") == 0);
                     CHECK(j_nonobject_const.count("foo") == 0);
                 }
@@ -936,7 +936,7 @@ TEST_CASE("element access 2")
                 SECTION("object")
                 {
                     json j_nonobject(json::value_t::object);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::object);
                     CHECK(j_nonobject.count("foo") == 0);
                     CHECK(j_nonobject_const.count("foo") == 0);
                 }
@@ -944,7 +944,7 @@ TEST_CASE("element access 2")
                 SECTION("array")
                 {
                     json j_nonobject(json::value_t::array);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::array);
                     CHECK(j_nonobject.count("foo") == 0);
                     CHECK(j_nonobject_const.count("foo") == 0);
                 }
@@ -952,7 +952,7 @@ TEST_CASE("element access 2")
                 SECTION("boolean")
                 {
                     json j_nonobject(json::value_t::boolean);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::boolean);
                     CHECK(j_nonobject.count("foo") == 0);
                     CHECK(j_nonobject_const.count("foo") == 0);
                 }
@@ -960,7 +960,7 @@ TEST_CASE("element access 2")
                 SECTION("number (integer)")
                 {
                     json j_nonobject(json::value_t::number_integer);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::number_integer);
                     CHECK(j_nonobject.count("foo") == 0);
                     CHECK(j_nonobject_const.count("foo") == 0);
                 }
@@ -968,7 +968,7 @@ TEST_CASE("element access 2")
                 SECTION("number (unsigned)")
                 {
                     json j_nonobject(json::value_t::number_unsigned);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::number_unsigned);
                     CHECK(j_nonobject.count("foo") == 0);
                     CHECK(j_nonobject_const.count("foo") == 0);
                 }
@@ -976,7 +976,7 @@ TEST_CASE("element access 2")
                 SECTION("number (floating-point)")
                 {
                     json j_nonobject(json::value_t::number_float);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::number_float);
                     CHECK(j_nonobject.count("foo") == 0);
                     CHECK(j_nonobject_const.count("foo") == 0);
                 }
@@ -987,7 +987,7 @@ TEST_CASE("element access 2")
         {
             SECTION("existing element")
             {
-                for (auto key :
+                for (const auto* key :
                         {"integer", "unsigned", "floating", "null", "string", "boolean", "object", "array"
                         })
                 {
@@ -1007,7 +1007,7 @@ TEST_CASE("element access 2")
                 SECTION("null")
                 {
                     json j_nonobject(json::value_t::null);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::null);
                     CHECK(j_nonobject.contains("foo") == false);
                     CHECK(j_nonobject_const.contains("foo") == false);
                 }
@@ -1015,7 +1015,7 @@ TEST_CASE("element access 2")
                 SECTION("string")
                 {
                     json j_nonobject(json::value_t::string);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::string);
                     CHECK(j_nonobject.contains("foo") == false);
                     CHECK(j_nonobject_const.contains("foo") == false);
                 }
@@ -1023,7 +1023,7 @@ TEST_CASE("element access 2")
                 SECTION("object")
                 {
                     json j_nonobject(json::value_t::object);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::object);
                     CHECK(j_nonobject.contains("foo") == false);
                     CHECK(j_nonobject_const.contains("foo") == false);
                 }
@@ -1031,7 +1031,7 @@ TEST_CASE("element access 2")
                 SECTION("array")
                 {
                     json j_nonobject(json::value_t::array);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::array);
                     CHECK(j_nonobject.contains("foo") == false);
                     CHECK(j_nonobject_const.contains("foo") == false);
                 }
@@ -1039,7 +1039,7 @@ TEST_CASE("element access 2")
                 SECTION("boolean")
                 {
                     json j_nonobject(json::value_t::boolean);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::boolean);
                     CHECK(j_nonobject.contains("foo") == false);
                     CHECK(j_nonobject_const.contains("foo") == false);
                 }
@@ -1047,7 +1047,7 @@ TEST_CASE("element access 2")
                 SECTION("number (integer)")
                 {
                     json j_nonobject(json::value_t::number_integer);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::number_integer);
                     CHECK(j_nonobject.contains("foo") == false);
                     CHECK(j_nonobject_const.contains("foo") == false);
                 }
@@ -1055,7 +1055,7 @@ TEST_CASE("element access 2")
                 SECTION("number (unsigned)")
                 {
                     json j_nonobject(json::value_t::number_unsigned);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::number_unsigned);
                     CHECK(j_nonobject.contains("foo") == false);
                     CHECK(j_nonobject_const.contains("foo") == false);
                 }
@@ -1063,7 +1063,7 @@ TEST_CASE("element access 2")
                 SECTION("number (floating-point)")
                 {
                     json j_nonobject(json::value_t::number_float);
-                    const json j_nonobject_const(j_nonobject);
+                    const json j_nonobject_const(json::value_t::number_float);
                     CHECK(j_nonobject.contains("foo") == false);
                     CHECK(j_nonobject_const.contains("foo") == false);
                 }
@@ -1078,7 +1078,7 @@ TEST_CASE("element access 2 (throwing tests)")
     SECTION("object")
     {
         json j = {{"integer", 1}, {"unsigned", 1u}, {"floating", 42.23}, {"null", nullptr}, {"string", "hello world"}, {"boolean", true}, {"object", json::object()}, {"array", {1, 2, 3}}};
-        const json j_const = j;
+        const json j_const = {{"integer", 1}, {"unsigned", 1u}, {"floating", 42.23}, {"null", nullptr}, {"string", "hello world"}, {"boolean", true}, {"object", json::object()}, {"array", {1, 2, 3}}};
 
         SECTION("access specified element with default value")
         {

test/src/unit-items.cpp

@@ -48,7 +48,7 @@ TEST_CASE("iterator_wrapper")
             json j = { {"A", 1}, {"B", 2} };
             int counter = 1;
 
-            for (auto i : json::iterator_wrapper(j))
+            for (auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -125,7 +125,7 @@ TEST_CASE("iterator_wrapper")
             json j = { {"A", 1}, {"B", 2} };
             int counter = 1;
 
-            for (const auto i : json::iterator_wrapper(j))
+            for (const auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -194,7 +194,7 @@ TEST_CASE("iterator_wrapper")
             const json j = { {"A", 1}, {"B", 2} };
             int counter = 1;
 
-            for (auto i : json::iterator_wrapper(j))
+            for (auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -260,7 +260,7 @@ TEST_CASE("iterator_wrapper")
             const json j = { {"A", 1}, {"B", 2} };
             int counter = 1;
 
-            for (const auto i : json::iterator_wrapper(j))
+            for (const auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -329,7 +329,7 @@ TEST_CASE("iterator_wrapper")
             json j = { "A", "B" };
             int counter = 1;
 
-            for (auto i : json::iterator_wrapper(j))
+            for (auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -406,7 +406,7 @@ TEST_CASE("iterator_wrapper")
             json j = { "A", "B" };
             int counter = 1;
 
-            for (const auto i : json::iterator_wrapper(j))
+            for (const auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -475,7 +475,7 @@ TEST_CASE("iterator_wrapper")
             const json j = { "A", "B" };
             int counter = 1;
 
-            for (auto i : json::iterator_wrapper(j))
+            for (auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -541,7 +541,7 @@ TEST_CASE("iterator_wrapper")
             const json j = { "A", "B" };
             int counter = 1;
 
-            for (const auto i : json::iterator_wrapper(j))
+            for (const auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -610,7 +610,7 @@ TEST_CASE("iterator_wrapper")
             json j = 1;
             int counter = 1;
 
-            for (auto i : json::iterator_wrapper(j))
+            for (auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 ++counter;
                 CHECK(i.key() == "");
@@ -646,7 +646,7 @@ TEST_CASE("iterator_wrapper")
             json j = 1;
             int counter = 1;
 
-            for (const auto i : json::iterator_wrapper(j))
+            for (const auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 ++counter;
                 CHECK(i.key() == "");
@@ -679,7 +679,7 @@ TEST_CASE("iterator_wrapper")
             const json j = 1;
             int counter = 1;
 
-            for (auto i : json::iterator_wrapper(j))
+            for (auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 ++counter;
                 CHECK(i.key() == "");
@@ -709,7 +709,7 @@ TEST_CASE("iterator_wrapper")
             const json j = 1;
             int counter = 1;
 
-            for (const auto i : json::iterator_wrapper(j))
+            for (const auto i : json::iterator_wrapper(j)) // NOLINT(performance-for-range-copy)
             {
                 ++counter;
                 CHECK(i.key() == "");
@@ -745,7 +745,7 @@ TEST_CASE("items()")
             json j = { {"A", 1}, {"B", 2} };
             int counter = 1;
 
-            for (auto i : j.items())
+            for (auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -822,7 +822,7 @@ TEST_CASE("items()")
             json j = { {"A", 1}, {"B", 2} };
             int counter = 1;
 
-            for (const auto i : j.items())
+            for (const auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -907,7 +907,7 @@ TEST_CASE("items()")
             const json j = { {"A", 1}, {"B", 2} };
             int counter = 1;
 
-            for (auto i : j.items())
+            for (auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -973,7 +973,7 @@ TEST_CASE("items()")
             const json j = { {"A", 1}, {"B", 2} };
             int counter = 1;
 
-            for (const auto i : j.items())
+            for (const auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -1042,7 +1042,7 @@ TEST_CASE("items()")
             json j = { "A", "B" };
             int counter = 1;
 
-            for (auto i : j.items())
+            for (auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -1119,7 +1119,7 @@ TEST_CASE("items()")
             json j = { "A", "B" };
             int counter = 1;
 
-            for (const auto i : j.items())
+            for (const auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -1188,7 +1188,7 @@ TEST_CASE("items()")
             const json j = { "A", "B" };
             int counter = 1;
 
-            for (auto i : j.items())
+            for (auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -1254,7 +1254,7 @@ TEST_CASE("items()")
             const json j = { "A", "B" };
             int counter = 1;
 
-            for (const auto i : j.items())
+            for (const auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 switch (counter++)
                 {
@@ -1323,7 +1323,7 @@ TEST_CASE("items()")
             json j = 1;
             int counter = 1;
 
-            for (auto i : j.items())
+            for (auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 ++counter;
                 CHECK(i.key() == "");
@@ -1359,7 +1359,7 @@ TEST_CASE("items()")
             json j = 1;
             int counter = 1;
 
-            for (const auto i : j.items())
+            for (const auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 ++counter;
                 CHECK(i.key() == "");
@@ -1392,7 +1392,7 @@ TEST_CASE("items()")
             const json j = 1;
             int counter = 1;
 
-            for (auto i : j.items())
+            for (auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 ++counter;
                 CHECK(i.key() == "");
@@ -1422,7 +1422,7 @@ TEST_CASE("items()")
             const json j = 1;
             int counter = 1;
 
-            for (const auto i : j.items())
+            for (const auto i : j.items()) // NOLINT(performance-for-range-copy)
             {
                 ++counter;
                 CHECK(i.key() == "");

test/src/unit-iterators2.cpp

@@ -90,6 +90,16 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_AS(it1_c < it2_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it2_c < it3_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it1_c < it3_c, json::invalid_iterator&);
+#if JSON_DIAGNOSTICS
+                    CHECK_THROWS_WITH(it1 < it1, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 < it2, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2 < it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 < it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c < it1_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c < it2_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2_c < it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c < it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+#else
                     CHECK_THROWS_WITH(it1 < it1, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1 < it2, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2 < it3, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
@@ -98,6 +108,7 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_WITH(it1_c < it2_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2_c < it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1_c < it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
+#endif
                 }
                 else
                 {
@@ -124,6 +135,16 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_AS(it1_c <= it2_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it2_c <= it3_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it1_c <= it3_c, json::invalid_iterator&);
+#if JSON_DIAGNOSTICS
+                    CHECK_THROWS_WITH(it1 <= it1, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 <= it2, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2 <= it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 <= it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c <= it1_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c <= it2_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2_c <= it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c <= it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+#else
                     CHECK_THROWS_WITH(it1 <= it1, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1 <= it2, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2 <= it3, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
@@ -132,6 +153,7 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_WITH(it1_c <= it2_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2_c <= it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1_c <= it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
+#endif
                 }
                 else
                 {
@@ -159,6 +181,16 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_AS(it1_c > it2_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it2_c > it3_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it1_c > it3_c, json::invalid_iterator&);
+#if JSON_DIAGNOSTICS
+                    CHECK_THROWS_WITH(it1 > it1, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 > it2, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2 > it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 > it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c > it1_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c > it2_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2_c > it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c > it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+#else
                     CHECK_THROWS_WITH(it1 > it1, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1 > it2, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2 > it3, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
@@ -167,6 +199,7 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_WITH(it1_c > it2_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2_c > it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1_c > it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
+#endif
                 }
                 else
                 {
@@ -194,6 +227,16 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_AS(it1_c >= it2_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it2_c >= it3_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it1_c >= it3_c, json::invalid_iterator&);
+#if JSON_DIAGNOSTICS
+                    CHECK_THROWS_WITH(it1 >= it1, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 >= it2, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2 >= it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 >= it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c >= it1_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c >= it2_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2_c >= it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c >= it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+#else
                     CHECK_THROWS_WITH(it1 >= it1, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1 >= it2, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2 >= it3, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
@@ -202,6 +245,7 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_WITH(it1_c >= it2_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2_c >= it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1_c >= it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
+#endif
                 }
                 else
                 {
@@ -227,13 +271,16 @@ TEST_CASE("iterators 2")
                 {
                     CHECK_THROWS_AS(j.begin() == k.begin(), json::invalid_iterator&);
                     CHECK_THROWS_AS(j.cbegin() == k.cbegin(), json::invalid_iterator&);
-                    CHECK_THROWS_WITH(j.begin() == k.begin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
-                    CHECK_THROWS_WITH(j.cbegin() == k.cbegin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
-
                     CHECK_THROWS_AS(j.begin() < k.begin(), json::invalid_iterator&);
                     CHECK_THROWS_AS(j.cbegin() < k.cbegin(), json::invalid_iterator&);
+#if JSON_DIAGNOSTICS
+                    // the output differs in each loop, so we cannot fix a string for the expected exception
+#else
+                    CHECK_THROWS_WITH(j.begin() == k.begin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
+                    CHECK_THROWS_WITH(j.cbegin() == k.cbegin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
                     CHECK_THROWS_WITH(j.begin() < k.begin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
                     CHECK_THROWS_WITH(j.cbegin() < k.cbegin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
+#endif
                 }
             }
         }
@@ -525,6 +572,16 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_AS(it1_c < it2_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it2_c < it3_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it1_c < it3_c, json::invalid_iterator&);
+#if JSON_DIAGNOSTICS
+                    CHECK_THROWS_WITH(it1 < it1, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 < it2, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2 < it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 < it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c < it1_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c < it2_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2_c < it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c < it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+#else
                     CHECK_THROWS_WITH(it1 < it1, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1 < it2, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2 < it3, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
@@ -533,6 +590,7 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_WITH(it1_c < it2_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2_c < it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1_c < it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
+#endif
                 }
                 else
                 {
@@ -559,6 +617,16 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_AS(it1_c <= it2_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it2_c <= it3_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it1_c <= it3_c, json::invalid_iterator&);
+#if JSON_DIAGNOSTICS
+                    CHECK_THROWS_WITH(it1 <= it1, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 <= it2, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2 <= it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 <= it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c <= it1_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c <= it2_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2_c <= it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c <= it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+#else
                     CHECK_THROWS_WITH(it1 <= it1, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1 <= it2, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2 <= it3, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
@@ -567,6 +635,7 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_WITH(it1_c <= it2_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2_c <= it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1_c <= it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
+#endif
                 }
                 else
                 {
@@ -594,6 +663,16 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_AS(it1_c > it2_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it2_c > it3_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it1_c > it3_c, json::invalid_iterator&);
+#if JSON_DIAGNOSTICS
+                    CHECK_THROWS_WITH(it1 > it1, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 > it2, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2 > it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 > it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c > it1_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c > it2_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2_c > it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c > it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+#else
                     CHECK_THROWS_WITH(it1 > it1, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1 > it2, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2 > it3, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
@@ -602,6 +681,7 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_WITH(it1_c > it2_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2_c > it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1_c > it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
+#endif
                 }
                 else
                 {
@@ -629,6 +709,16 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_AS(it1_c >= it2_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it2_c >= it3_c, json::invalid_iterator&);
                     CHECK_THROWS_AS(it1_c >= it3_c, json::invalid_iterator&);
+#if JSON_DIAGNOSTICS
+                    CHECK_THROWS_WITH(it1 >= it1, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 >= it2, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2 >= it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1 >= it3, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c >= it1_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c >= it2_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it2_c >= it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+                    CHECK_THROWS_WITH(it1_c >= it3_c, "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators");
+#else
                     CHECK_THROWS_WITH(it1 >= it1, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1 >= it2, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2 >= it3, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
@@ -637,6 +727,7 @@ TEST_CASE("iterators 2")
                     CHECK_THROWS_WITH(it1_c >= it2_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it2_c >= it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
                     CHECK_THROWS_WITH(it1_c >= it3_c, "[json.exception.invalid_iterator.213] cannot compare order of object iterators");
+#endif
                 }
                 else
                 {
@@ -662,13 +753,16 @@ TEST_CASE("iterators 2")
                 {
                     CHECK_THROWS_AS(j.rbegin() == k.rbegin(), json::invalid_iterator&);
                     CHECK_THROWS_AS(j.crbegin() == k.crbegin(), json::invalid_iterator&);
-                    CHECK_THROWS_WITH(j.rbegin() == k.rbegin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
-                    CHECK_THROWS_WITH(j.crbegin() == k.crbegin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
-
                     CHECK_THROWS_AS(j.rbegin() < k.rbegin(), json::invalid_iterator&);
                     CHECK_THROWS_AS(j.crbegin() < k.crbegin(), json::invalid_iterator&);
+#if JSON_DIAGNOSTICS
+                    // the output differs in each loop, so we cannot fix a string for the expected exception
+#else
+                    CHECK_THROWS_WITH(j.rbegin() == k.rbegin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
+                    CHECK_THROWS_WITH(j.crbegin() == k.crbegin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
                     CHECK_THROWS_WITH(j.rbegin() < k.rbegin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
                     CHECK_THROWS_WITH(j.crbegin() < k.crbegin(), "[json.exception.invalid_iterator.212] cannot compare iterators of different containers");
+#endif
                 }
             }
         }

test/src/unit-json_patch.cpp

@@ -343,7 +343,11 @@ TEST_CASE("JSON patch")
 
             // check that evaluation throws
             CHECK_THROWS_AS(doc.patch(patch), json::other_error&);
+#if JSON_DIAGNOSTICS
+            CHECK_THROWS_WITH_STD_STR(doc.patch(patch), "[json.exception.other_error.501] (/0) unsuccessful: " + patch[0].dump());
+#else
             CHECK_THROWS_WITH_STD_STR(doc.patch(patch), "[json.exception.other_error.501] unsuccessful: " + patch[0].dump());
+#endif
         }
 
         SECTION("A.10. Adding a Nested Member Object")
@@ -484,7 +488,11 @@ TEST_CASE("JSON patch")
 
             // check that evaluation throws
             CHECK_THROWS_AS(doc.patch(patch), json::other_error&);
+#if JSON_DIAGNOSTICS
+            CHECK_THROWS_WITH_STD_STR(doc.patch(patch), "[json.exception.other_error.501] (/0) unsuccessful: " + patch[0].dump());
+#else
             CHECK_THROWS_WITH_STD_STR(doc.patch(patch), "[json.exception.other_error.501] unsuccessful: " + patch[0].dump());
+#endif
         }
 
         SECTION("A.16. Adding an Array Value")
@@ -683,8 +691,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {"op", "add", "path", "", "value", 1};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.104] parse error: JSON patch must be an array of objects");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.104] parse error: (/0) JSON patch must be an array of objects");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.104] parse error: JSON patch must be an array of objects");
+#endif
             }
 
             SECTION("missing 'op'")
@@ -692,8 +703,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"foo", "bar"}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation must have member 'op'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation must have member 'op'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation must have member 'op'");
+#endif
             }
 
             SECTION("non-string 'op'")
@@ -701,8 +715,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", 1}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation must have string member 'op'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation must have string member 'op'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation must have string member 'op'");
+#endif
             }
 
             SECTION("invalid operation")
@@ -710,8 +727,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "foo"}, {"path", ""}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation value 'foo' is invalid");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation value 'foo' is invalid");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation value 'foo' is invalid");
+#endif
             }
         }
 
@@ -722,8 +742,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "add"}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'add' must have member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'add' must have member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'add' must have member 'path'");
+#endif
             }
 
             SECTION("non-string 'path'")
@@ -731,8 +754,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "add"}, {"path", 1}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'add' must have string member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'add' must have string member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'add' must have string member 'path'");
+#endif
             }
 
             SECTION("missing 'value'")
@@ -740,8 +766,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "add"}, {"path", ""}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'add' must have member 'value'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'add' must have member 'value'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'add' must have member 'value'");
+#endif
             }
 
             SECTION("invalid array index")
@@ -761,8 +790,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "remove"}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'remove' must have member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'remove' must have member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'remove' must have member 'path'");
+#endif
             }
 
             SECTION("non-string 'path'")
@@ -770,8 +802,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "remove"}, {"path", 1}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'remove' must have string member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'remove' must have string member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'remove' must have string member 'path'");
+#endif
             }
 
             SECTION("nonexisting target location (array)")
@@ -809,8 +844,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "replace"}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'replace' must have member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'replace' must have member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'replace' must have member 'path'");
+#endif
             }
 
             SECTION("non-string 'path'")
@@ -818,8 +856,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "replace"}, {"path", 1}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'replace' must have string member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'replace' must have string member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'replace' must have string member 'path'");
+#endif
             }
 
             SECTION("missing 'value'")
@@ -827,8 +868,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "replace"}, {"path", ""}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'replace' must have member 'value'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'replace' must have member 'value'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'replace' must have member 'value'");
+#endif
             }
 
             SECTION("nonexisting target location (array)")
@@ -857,8 +901,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "move"}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'move' must have member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'move' must have member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'move' must have member 'path'");
+#endif
             }
 
             SECTION("non-string 'path'")
@@ -866,8 +913,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "move"}, {"path", 1}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'move' must have string member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'move' must have string member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'move' must have string member 'path'");
+#endif
             }
 
             SECTION("missing 'from'")
@@ -875,8 +925,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "move"}, {"path", ""}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'move' must have member 'from'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'move' must have member 'from'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'move' must have member 'from'");
+#endif
             }
 
             SECTION("non-string 'from'")
@@ -884,8 +937,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "move"}, {"path", ""}, {"from", 1}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'move' must have string member 'from'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'move' must have string member 'from'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'move' must have string member 'from'");
+#endif
             }
 
             SECTION("nonexisting from location (array)")
@@ -914,8 +970,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "copy"}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'copy' must have member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'copy' must have member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'copy' must have member 'path'");
+#endif
             }
 
             SECTION("non-string 'path'")
@@ -923,8 +982,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "copy"}, {"path", 1}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'copy' must have string member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'copy' must have string member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'copy' must have string member 'path'");
+#endif
             }
 
             SECTION("missing 'from'")
@@ -932,8 +994,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "copy"}, {"path", ""}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'copy' must have member 'from'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'copy' must have member 'from'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'copy' must have member 'from'");
+#endif
             }
 
             SECTION("non-string 'from'")
@@ -941,8 +1006,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "copy"}, {"path", ""}, {"from", 1}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'copy' must have string member 'from'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'copy' must have string member 'from'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'copy' must have string member 'from'");
+#endif
             }
 
             SECTION("nonexisting from location (array)")
@@ -971,8 +1039,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "test"}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'test' must have member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'test' must have member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'test' must have member 'path'");
+#endif
             }
 
             SECTION("non-string 'path'")
@@ -980,8 +1051,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "test"}, {"path", 1}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'test' must have string member 'path'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'test' must have string member 'path'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'test' must have string member 'path'");
+#endif
             }
 
             SECTION("missing 'value'")
@@ -989,8 +1063,11 @@ TEST_CASE("JSON patch")
                 json j;
                 json patch = {{{"op", "test"}, {"path", ""}}};
                 CHECK_THROWS_AS(j.patch(patch), json::parse_error&);
-                CHECK_THROWS_WITH(j.patch(patch),
-                                  "[json.exception.parse_error.105] parse error: operation 'test' must have member 'value'");
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: (/0) operation 'test' must have member 'value'");
+#else
+                CHECK_THROWS_WITH(j.patch(patch), "[json.exception.parse_error.105] parse error: operation 'test' must have member 'value'");
+#endif
             }
         }
     }
@@ -1183,7 +1260,11 @@ TEST_CASE("JSON patch")
 
                 // the test will fail
                 CHECK_THROWS_AS(doc.patch(patch), json::other_error&);
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_STD_STR(doc.patch(patch), "[json.exception.other_error.501] (/0) unsuccessful: " + patch[0].dump());
+#else
                 CHECK_THROWS_WITH_STD_STR(doc.patch(patch), "[json.exception.other_error.501] unsuccessful: " + patch[0].dump());
+#endif
             }
         }
     }
@@ -1258,7 +1339,7 @@ TEST_CASE("JSON patch")
 
     SECTION("Tests from github.com/json-patch/json-patch-tests")
     {
-        for (auto filename :
+        for (const auto* filename :
                 {
                     TEST_DATA_DIRECTORY "/json-patch-tests/spec_tests.json",
                     TEST_DATA_DIRECTORY "/json-patch-tests/tests.json"

test/src/unit-json_pointer.cpp

@@ -504,8 +504,11 @@ TEST_CASE("JSON pointers")
 
         // error for nonprimitve values
         CHECK_THROWS_AS(json({{"/1", {1, 2, 3}}}).unflatten(), json::type_error&);
-        CHECK_THROWS_WITH(json({{"/1", {1, 2, 3}}}).unflatten(),
-        "[json.exception.type_error.315] values in object must be primitive");
+#if JSON_DIAGNOSTICS
+        CHECK_THROWS_WITH(json({{"/1", {1, 2, 3}}}).unflatten(), "[json.exception.type_error.315] (/~11) values in object must be primitive");
+#else
+        CHECK_THROWS_WITH(json({{"/1", {1, 2, 3}}}).unflatten(), "[json.exception.type_error.315] values in object must be primitive");
+#endif
 
         // error for conflicting values
         json j_error = {{"", 42}, {"/foo", 17}};
@@ -535,7 +538,7 @@ TEST_CASE("JSON pointers")
 
     SECTION("string representation")
     {
-        for (auto ptr :
+        for (const auto* ptr :
                 {"", "/foo", "/foo/0", "/", "/a~1b", "/c%d", "/e^f", "/g|h", "/i\\j", "/k\"l", "/ ", "/m~0n"
                 })
         {

test/src/unit-msgpack.cpp

@@ -52,42 +52,42 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool boolean(bool)
+    bool boolean(bool /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_integer(json::number_integer_t)
+    bool number_integer(json::number_integer_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_unsigned(json::number_unsigned_t)
+    bool number_unsigned(json::number_unsigned_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_float(json::number_float_t, const std::string&)
+    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool string(std::string&)
+    bool string(std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool binary(std::vector<std::uint8_t>&)
+    bool binary(std::vector<std::uint8_t>& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool start_object(std::size_t)
+    bool start_object(std::size_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool key(std::string&)
+    bool key(std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
@@ -97,7 +97,7 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool start_array(std::size_t)
+    bool start_array(std::size_t /*unused*/)
     {
         return events_left-- > 0;
     }
@@ -107,7 +107,7 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool parse_error(std::size_t, const std::string&, const json::exception&)
+    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/) // NOLINT(readability-convert-member-functions-to-static)
     {
         return false;
     }
@@ -115,7 +115,7 @@ class SaxCountdown
   private:
     int events_left = 0;
 };
-}
+} // namespace
 
 TEST_CASE("MessagePack")
 {
@@ -258,7 +258,7 @@ TEST_CASE("MessagePack")
 
                         // check individual bytes
                         CHECK(result[0] == 0xcc);
-                        uint8_t restored = static_cast<uint8_t>(result[1]);
+                        auto restored = static_cast<uint8_t>(result[1]);
                         CHECK(restored == i);
 
                         // roundtrip
@@ -293,7 +293,7 @@ TEST_CASE("MessagePack")
 
                         // check individual bytes
                         CHECK(result[0] == 0xcd);
-                        uint16_t restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        auto restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
                         CHECK(restored == i);
 
                         // roundtrip
@@ -436,7 +436,7 @@ TEST_CASE("MessagePack")
                     const auto result = json::to_msgpack(j);
                     CHECK(result == expected);
 
-                    int16_t restored = static_cast<int16_t>((result[1] << 8) + result[2]);
+                    auto restored = static_cast<int16_t>((result[1] << 8) + result[2]);
                     CHECK(restored == -9263);
 
                     // roundtrip
@@ -446,7 +446,7 @@ TEST_CASE("MessagePack")
 
                 SECTION("-32768..-129 (int 16)")
                 {
-                    for (int16_t i = -32768; i <= -129; ++i)
+                    for (int16_t i = -32768; i <= int16_t(-129); ++i)
                     {
                         CAPTURE(i)
 
@@ -469,7 +469,7 @@ TEST_CASE("MessagePack")
 
                         // check individual bytes
                         CHECK(result[0] == 0xd1);
-                        int16_t restored = static_cast<int16_t>((result[1] << 8) + result[2]);
+                        auto restored = static_cast<int16_t>((result[1] << 8) + result[2]);
                         CHECK(restored == i);
 
                         // roundtrip
@@ -485,7 +485,7 @@ TEST_CASE("MessagePack")
                     numbers.push_back(-65536);
                     numbers.push_back(-77777);
                     numbers.push_back(-1048576);
-                    numbers.push_back(-2147483648ll);
+                    numbers.push_back(-2147483648LL);
                     for (auto i : numbers)
                     {
                         CAPTURE(i)
@@ -527,7 +527,7 @@ TEST_CASE("MessagePack")
                 {
                     std::vector<int64_t> numbers;
                     numbers.push_back(INT64_MIN);
-                    numbers.push_back(-2147483649ll);
+                    numbers.push_back(-2147483649LL);
                     for (auto i : numbers)
                     {
                         CAPTURE(i)
@@ -630,7 +630,7 @@ TEST_CASE("MessagePack")
 
                         // check individual bytes
                         CHECK(result[0] == 0xcc);
-                        uint8_t restored = static_cast<uint8_t>(result[1]);
+                        auto restored = static_cast<uint8_t>(result[1]);
                         CHECK(restored == i);
 
                         // roundtrip
@@ -664,7 +664,7 @@ TEST_CASE("MessagePack")
 
                         // check individual bytes
                         CHECK(result[0] == 0xcd);
-                        uint16_t restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        auto restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
                         CHECK(restored == i);
 
                         // roundtrip
@@ -1088,7 +1088,7 @@ TEST_CASE("MessagePack")
 
             SECTION("{\"a\": {\"b\": {\"c\": {}}}}")
             {
-                json j = json::parse("{\"a\": {\"b\": {\"c\": {}}}}");
+                json j = json::parse(R"({"a": {"b": {"c": {}}}})");
                 std::vector<uint8_t> expected =
                 {
                     0x81, 0xa1, 0x61, 0x81, 0xa1, 0x62, 0x81, 0xa1, 0x63, 0x80
@@ -1647,23 +1647,21 @@ TEST_CASE("MessagePack roundtrips" * doctest::skip())
     SECTION("input from msgpack-python")
     {
         // most of these are excluded due to differences in key order (not a real problem)
-        auto exclude_packed = std::set<std::string>
-        {
-            TEST_DATA_DIRECTORY "/json.org/1.json",
-            TEST_DATA_DIRECTORY "/json.org/2.json",
-            TEST_DATA_DIRECTORY "/json.org/3.json",
-            TEST_DATA_DIRECTORY "/json.org/4.json",
-            TEST_DATA_DIRECTORY "/json.org/5.json",
-            TEST_DATA_DIRECTORY "/json_testsuite/sample.json", // kills AppVeyor
-            TEST_DATA_DIRECTORY "/json_tests/pass1.json",
-            TEST_DATA_DIRECTORY "/regression/working_file.json",
-            TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object.json",
-            TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_basic.json",
-            TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_duplicated_key.json",
-            TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_long_strings.json",
-            TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_simple.json",
-            TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_string_unicode.json",
-        };
+        std::set<std::string> exclude_packed;
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json.org/1.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json.org/2.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json.org/3.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json.org/4.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json.org/5.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json_testsuite/sample.json"); // kills AppVeyor
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/json_tests/pass1.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/regression/working_file.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_basic.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_duplicated_key.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_long_strings.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_simple.json");
+        exclude_packed.insert(TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_object_string_unicode.json");
 
         for (std::string filename :
                 {
@@ -1870,7 +1868,7 @@ TEST_CASE("MessagePack roundtrips" * doctest::skip())
                 // parse MessagePack file
                 auto packed = utils::read_binary_file(filename + ".msgpack");
 
-                if (!exclude_packed.count(filename))
+                if (exclude_packed.count(filename) == 0u)
                 {
                     {
                         INFO_WITH_TEMP(filename + ": output adapters: std::vector<uint8_t>");

test/src/unit-noexcept.cpp

@@ -42,16 +42,16 @@ enum test
 struct pod {};
 struct pod_bis {};
 
-void to_json(json&, pod) noexcept;
-void to_json(json&, pod_bis);
-void from_json(const json&, pod) noexcept;
-void from_json(const json&, pod_bis);
-void to_json(json&, pod) noexcept {}
-void to_json(json&, pod_bis) {}
-void from_json(const json&, pod) noexcept {}
-void from_json(const json&, pod_bis) {}
+void to_json(json& /*unused*/, pod /*unused*/) noexcept;
+void to_json(json& /*unused*/, pod_bis /*unused*/);
+void from_json(const json& /*unused*/, pod /*unused*/) noexcept;
+void from_json(const json& /*unused*/, pod_bis /*unused*/);
+void to_json(json& /*unused*/, pod /*unused*/) noexcept {}
+void to_json(json& /*unused*/, pod_bis /*unused*/) {}
+void from_json(const json& /*unused*/, pod /*unused*/) noexcept {}
+void from_json(const json& /*unused*/, pod_bis /*unused*/) {}
 
-static json* j = nullptr;
+json* j = nullptr;
 
 static_assert(noexcept(json{}), "");
 static_assert(noexcept(nlohmann::to_json(*j, 2)), "");
@@ -66,7 +66,7 @@ static_assert(noexcept(json(pod{})), "");
 static_assert(noexcept(j->get<pod>()), "");
 static_assert(!noexcept(j->get<pod_bis>()), "");
 static_assert(noexcept(json(pod{})), "");
-}
+} // namespace
 
 TEST_CASE("runtime checks")
 {

test/src/unit-ordered_map.cpp

@@ -49,6 +49,7 @@ TEST_CASE("ordered_map")
             std::map<std::string, std::string> m {{"eins", "one"}, {"zwei", "two"}, {"drei", "three"}};
             ordered_map<std::string, std::string> om(m.begin(), m.end());
             const auto com = om;
+            om.clear(); // silence a warning by forbidding having "const auto& com = om;"
             CHECK(com.size() == 3);
         }
     }

test/src/unit-readme.cpp

@@ -52,7 +52,7 @@ TEST_CASE("README" * doctest::skip())
 {
     {
         // redirect std::cout for the README file
-        auto old_cout_buffer = std::cout.rdbuf();
+        auto* old_cout_buffer = std::cout.rdbuf();
         std::ostringstream new_stream;
         std::cout.rdbuf(new_stream.rdbuf());
         {
@@ -123,7 +123,7 @@ TEST_CASE("README" * doctest::skip())
 
         {
             // create object from string literal
-            json j = "{ \"happy\": true, \"pi\": 3.141 }"_json;
+            json j = "{ \"happy\": true, \"pi\": 3.141 }"_json; // NOLINT(modernize-raw-string-literal)
 
             // or even nicer with a raw string literal
             auto j2 = R"(
@@ -134,7 +134,7 @@ TEST_CASE("README" * doctest::skip())
         )"_json;
 
             // or explicitly
-            auto j3 = json::parse("{ \"happy\": true, \"pi\": 3.141 }");
+            auto j3 = json::parse(R"({"happy": true, "pi": 3.141})");
 
             // explicit conversion to string
             std::string s = j.dump();    // {\"happy\":true,\"pi\":3.141}
@@ -158,17 +158,17 @@ TEST_CASE("README" * doctest::skip())
             j.push_back(true);
 
             // comparison
-            bool x = (j == "[\"foo\", 1, true]"_json);  // true
+            bool x = (j == R"(["foo", 1, true])"_json);  // true
             CHECK(x == true);
 
             // iterate the array
-            for (json::iterator it = j.begin(); it != j.end(); ++it)
+            for (json::iterator it = j.begin(); it != j.end(); ++it) // NOLINT(modernize-loop-convert)
             {
                 std::cout << *it << '\n';
             }
 
             // range-based for
-            for (auto element : j)
+            for (auto& element : j)
             {
                 std::cout << element << '\n';
             }

test/src/unit-reference_access.cpp

@@ -56,11 +56,11 @@ TEST_CASE("reference access")
         json value = {{"one", 1}, {"two", 2}};
 
         // check if references are returned correctly
-        test_type& p1 = value.get_ref<test_type&>();
+        auto& p1 = value.get_ref<test_type&>();
         CHECK(&p1 == value.get_ptr<test_type*>());
         CHECK(p1 == value.get<test_type>());
 
-        const test_type& p2 = value.get_ref<const test_type&>();
+        const auto& p2 = value.get_ref<const test_type&>();
         CHECK(&p2 == value.get_ptr<const test_type*>());
         CHECK(p2 == value.get<test_type>());
 
@@ -95,7 +95,7 @@ TEST_CASE("reference access")
         // test_type& p1 = value.get_ref<test_type&>();
 
         // check if references are returned correctly
-        const test_type& p2 = value.get_ref<const test_type&>();
+        const auto& p2 = value.get_ref<const test_type&>();
         CHECK(&p2 == value.get_ptr<const test_type*>());
         CHECK(p2 == value.get<test_type>());
     }
@@ -106,11 +106,11 @@ TEST_CASE("reference access")
         json value = {1, 2, 3, 4};
 
         // check if references are returned correctly
-        test_type& p1 = value.get_ref<test_type&>();
+        auto& p1 = value.get_ref<test_type&>();
         CHECK(&p1 == value.get_ptr<test_type*>());
         CHECK(p1 == value.get<test_type>());
 
-        const test_type& p2 = value.get_ref<const test_type&>();
+        const auto& p2 = value.get_ref<const test_type&>();
         CHECK(&p2 == value.get_ptr<const test_type*>());
         CHECK(p2 == value.get<test_type>());
 
@@ -142,11 +142,11 @@ TEST_CASE("reference access")
         json value = "hello";
 
         // check if references are returned correctly
-        test_type& p1 = value.get_ref<test_type&>();
+        auto& p1 = value.get_ref<test_type&>();
         CHECK(&p1 == value.get_ptr<test_type*>());
         CHECK(p1 == value.get<test_type>());
 
-        const test_type& p2 = value.get_ref<const test_type&>();
+        const auto& p2 = value.get_ref<const test_type&>();
         CHECK(&p2 == value.get_ptr<const test_type*>());
         CHECK(p2 == value.get<test_type>());
 
@@ -178,11 +178,11 @@ TEST_CASE("reference access")
         json value = false;
 
         // check if references are returned correctly
-        test_type& p1 = value.get_ref<test_type&>();
+        auto& p1 = value.get_ref<test_type&>();
         CHECK(&p1 == value.get_ptr<test_type*>());
         CHECK(p1 == value.get<test_type>());
 
-        const test_type& p2 = value.get_ref<const test_type&>();
+        const auto& p2 = value.get_ref<const test_type&>();
         CHECK(&p2 == value.get_ptr<const test_type*>());
         CHECK(p2 == value.get<test_type>());
 
@@ -214,11 +214,11 @@ TEST_CASE("reference access")
         json value = -23;
 
         // check if references are returned correctly
-        test_type& p1 = value.get_ref<test_type&>();
+        auto& p1 = value.get_ref<test_type&>();
         CHECK(&p1 == value.get_ptr<test_type*>());
         CHECK(p1 == value.get<test_type>());
 
-        const test_type& p2 = value.get_ref<const test_type&>();
+        const auto& p2 = value.get_ref<const test_type&>();
         CHECK(&p2 == value.get_ptr<const test_type*>());
         CHECK(p2 == value.get<test_type>());
 
@@ -250,11 +250,11 @@ TEST_CASE("reference access")
         json value = 23u;
 
         // check if references are returned correctly
-        test_type& p1 = value.get_ref<test_type&>();
+        auto& p1 = value.get_ref<test_type&>();
         CHECK(&p1 == value.get_ptr<test_type*>());
         CHECK(p1 == value.get<test_type>());
 
-        const test_type& p2 = value.get_ref<const test_type&>();
+        const auto& p2 = value.get_ref<const test_type&>();
         CHECK(&p2 == value.get_ptr<const test_type*>());
         CHECK(p2 == value.get<test_type>());
 
@@ -286,11 +286,11 @@ TEST_CASE("reference access")
         json value = 42.23;
 
         // check if references are returned correctly
-        test_type& p1 = value.get_ref<test_type&>();
+        auto& p1 = value.get_ref<test_type&>();
         CHECK(&p1 == value.get_ptr<test_type*>());
         CHECK(p1 == value.get<test_type>());
 
-        const test_type& p2 = value.get_ref<const test_type&>();
+        const auto& p2 = value.get_ref<const test_type&>();
         CHECK(&p2 == value.get_ptr<const test_type*>());
         CHECK(p2 == value.get<test_type>());
 

test/src/unit-regression1.cpp

@@ -94,7 +94,7 @@ template<typename T>
 struct foo_serializer < T, typename std::enable_if < !std::is_same<foo, T>::value >::type >
 {
     template <typename BasicJsonType>
-    static void to_json(BasicJsonType& j, const T& value) noexcept
+    static void to_json(BasicJsonType& j, const T& value) noexcept // NOLINT(bugprone-exception-escape)
     {
         ::nlohmann::to_json(j, value);
     }
@@ -104,7 +104,7 @@ struct foo_serializer < T, typename std::enable_if < !std::is_same<foo, T>::valu
         ::nlohmann::from_json(j, value);
     }
 };
-}
+} // namespace ns
 
 using foo_json = nlohmann::basic_json<std::map, std::vector, std::string, bool, std::int64_t,
       std::uint64_t, double, std::allocator, ns::foo_serializer, std::vector<std::uint8_t>>;
@@ -115,10 +115,13 @@ using foo_json = nlohmann::basic_json<std::map, std::vector, std::string, bool,
 
 namespace
 {
-struct nocopy
+struct nocopy // NOLINT(cppcoreguidelines-special-member-functions,hicpp-special-member-functions)
 {
     nocopy() = default;
     nocopy(const nocopy&) = delete;
+    nocopy(nocopy&&) = delete;
+    nocopy& operator=(const nocopy&) = delete;
+    nocopy& operator=(nocopy&&) = delete;
 
     int val = 0;
 
@@ -127,7 +130,7 @@ struct nocopy
         j = {{"val", n.val}};
     }
 };
-}
+} // namespace
 
 TEST_CASE("regression tests 1")
 {
@@ -135,7 +138,7 @@ TEST_CASE("regression tests 1")
     {
         SECTION("escape_doublequote")
         {
-            auto s = "[\"\\\"foo\\\"\"]";
+            const auto* s = R"(["\"foo\""])";
             json j = json::parse(s);
             auto expected = R"(["\"foo\""])"_json;
             CHECK(j == expected);
@@ -245,7 +248,7 @@ TEST_CASE("regression tests 1")
 
     SECTION("issue #82 - lexer::get_number return NAN")
     {
-        const auto content = R"(
+        const auto* const content = R"(
         {
             "Test":"Test1",
             "Number":100,
@@ -394,7 +397,11 @@ TEST_CASE("regression tests 1")
         // improve coverage
         o["int"] = 1;
         CHECK_THROWS_AS(s2 = o["int"], json::type_error);
+#if JSON_DIAGNOSTICS
+        CHECK_THROWS_WITH(s2 = o["int"], "[json.exception.type_error.302] (/int) type must be string, but is number");
+#else
         CHECK_THROWS_WITH(s2 = o["int"], "[json.exception.type_error.302] type must be string, but is number");
+#endif
     }
 #endif
 
@@ -408,18 +415,18 @@ TEST_CASE("regression tests 1")
         json j;
 
         // Non-const access with key as "char []"
-        char array_key[] = "Key1";
+        char array_key[] = "Key1"; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
         CHECK_NOTHROW(j[array_key] = 1);
         CHECK(j[array_key] == json(1));
 
         // Non-const access with key as "const char[]"
-        const char const_array_key[] = "Key2";
+        const char const_array_key[] = "Key2"; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
         CHECK_NOTHROW(j[const_array_key] = 2);
         CHECK(j[const_array_key] == json(2));
 
         // Non-const access with key as "char *"
-        char _ptr_key[] = "Key3";
-        char* ptr_key = &_ptr_key[0];
+        char _ptr_key[] = "Key3"; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
+        char* ptr_key = &_ptr_key[0]; // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
         CHECK_NOTHROW(j[ptr_key] = 3);
         CHECK(j[ptr_key] == json(3));
 
@@ -633,7 +640,7 @@ TEST_CASE("regression tests 1")
 
     SECTION("issue #306 - Parsing fails without space at end of file")
     {
-        for (auto filename :
+        for (const auto* filename :
                 {
                     TEST_DATA_DIRECTORY "/regression/broken_file.json",
                     TEST_DATA_DIRECTORY "/regression/working_file.json"
@@ -648,7 +655,7 @@ TEST_CASE("regression tests 1")
 
     SECTION("issue #310 - make json_benchmarks no longer working in 2.0.4")
     {
-        for (auto filename :
+        for (const auto* filename :
                 {
                     TEST_DATA_DIRECTORY "/regression/floats.json",
                     TEST_DATA_DIRECTORY "/regression/signed_ints.json",
@@ -732,7 +739,7 @@ TEST_CASE("regression tests 1")
         check_roundtrip(83623297654460.33);
         check_roundtrip(701466573254773.6);
         check_roundtrip(1369013370304513);
-        check_roundtrip(96963648023094720);
+        check_roundtrip(96963648023094720); // NOLINT(bugprone-narrowing-conversions,cppcoreguidelines-narrowing-conversions)
         check_roundtrip(3.478237409280108e+17);
     }
 
@@ -1099,17 +1106,17 @@ TEST_CASE("regression tests 1")
     SECTION("issue #414 - compare with literal 0)")
     {
 #define CHECK_TYPE(v) \
-    CHECK((json(v) == v));\
-    CHECK((v == json(v)));\
-    CHECK_FALSE((json(v) != v));\
-    CHECK_FALSE((v != json(v)));
+    CHECK((json(v) == (v)));\
+    CHECK(((v) == json(v)));\
+    CHECK_FALSE((json(v) != (v)));\
+    CHECK_FALSE(((v) != json(v)));
 
         CHECK_TYPE(nullptr)
         CHECK_TYPE(0)
         CHECK_TYPE(0u)
         CHECK_TYPE(0L)
         CHECK_TYPE(0.0)
-        CHECK_TYPE("")
+        CHECK_TYPE("") // NOLINT(readability-container-size-empty)
 
 #undef CHECK_TYPE
     }
@@ -1385,8 +1392,10 @@ TEST_CASE("regression tests 1")
     {
         SECTION("example 1")
         {
-            std::istringstream i1_2_3( "{\"first\": \"one\" }{\"second\": \"two\"}3" );
-            json j1, j2, j3;
+            std::istringstream i1_2_3( R"({"first": "one" }{"second": "two"}3)" );
+            json j1;
+            json j2;
+            json j3;
             i1_2_3 >> j1;
             i1_2_3 >> j2;
             i1_2_3 >> j3;
@@ -1441,8 +1450,8 @@ TEST_CASE("regression tests 1")
 
     SECTION("issue #838 - incorrect parse error with binary data in keys")
     {
-        uint8_t key1[] = { 103, 92, 117, 48, 48, 48, 55, 92, 114, 215, 126, 214, 95, 92, 34, 174, 40, 71, 38, 174, 40, 71, 38, 223, 134, 247, 127, 0 };
-        std::string key1_str(reinterpret_cast<char*>(key1));
+        std::array<uint8_t, 28> key1 = {{ 103, 92, 117, 48, 48, 48, 55, 92, 114, 215, 126, 214, 95, 92, 34, 174, 40, 71, 38, 174, 40, 71, 38, 223, 134, 247, 127, 0 }};
+        std::string key1_str(reinterpret_cast<char*>(key1.data()));
         json j = key1_str;
         CHECK_THROWS_AS(j.dump(), json::type_error&);
         CHECK_THROWS_WITH(j.dump(), "[json.exception.type_error.316] invalid UTF-8 byte at index 10: 0x7E");
@@ -1524,7 +1533,7 @@ TEST_CASE("regression tests 1")
     SECTION("issue #971 - Add a SAX parser - late bug")
     {
         // a JSON text
-        auto text = R"(
+        const auto* text = R"(
     {
         "Image": {
             "Width":  800,
@@ -1545,14 +1554,7 @@ TEST_CASE("regression tests 1")
         json::parser_callback_t cb = [](int /*depth*/, json::parse_event_t event, json & parsed)
         {
             // skip object elements with key "Thumbnail"
-            if (event == json::parse_event_t::key && parsed == json("Thumbnail"))
-            {
-                return false;
-            }
-            else
-            {
-                return true;
-            }
+            return !(event == json::parse_event_t::key && parsed == json("Thumbnail"));
         };
 
         // parse (with callback) and serialize JSON

test/src/unit-regression2.cpp

@@ -37,11 +37,9 @@ DOCTEST_GCC_SUPPRESS_WARNING("-Wfloat-equal")
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 
-#include <fstream>
-#include <sstream>
 #include <list>
 #include <cstdio>
-#include <test_data.hpp>
+#include <utility>
 
 #if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464
     #define JSON_HAS_CPP_17
@@ -68,19 +66,20 @@ namespace
 {
 struct NonDefaultFromJsonStruct { };
 
-inline bool operator== (NonDefaultFromJsonStruct const&, NonDefaultFromJsonStruct const&)
+inline bool operator== (NonDefaultFromJsonStruct const& /*unused*/, NonDefaultFromJsonStruct const& /*unused*/)
 {
     return true;
 }
 
 enum class for_1647 { one, two };
 
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays): this is a false positive
 NLOHMANN_JSON_SERIALIZE_ENUM(for_1647,
 {
     {for_1647::one, "one"},
     {for_1647::two, "two"},
 })
-}
+} // namespace
 
 /////////////////////////////////////////////////////////////////////
 // for #1299
@@ -89,17 +88,19 @@ NLOHMANN_JSON_SERIALIZE_ENUM(for_1647,
 struct Data
 {
     Data() = default;
-    Data(const std::string& a_, const std::string b_) : a(a_), b(b_) {}
+    Data(std::string a_, std::string b_) : a(std::move(a_)), b(std::move(b_)) {}
     std::string a {};
     std::string b {};
 };
 
+void from_json(const json& j, Data& data);
 void from_json(const json& j, Data& data)
 {
     j["a"].get_to(data.a);
     j["b"].get_to(data.b);
 }
 
+bool operator==(Data const& lhs, Data const& rhs);
 bool operator==(Data const& lhs, Data const& rhs)
 {
     return lhs.a == rhs.a && lhs.b == rhs.b;
@@ -115,12 +116,12 @@ namespace nlohmann
 template <>
 struct adl_serializer<NonDefaultFromJsonStruct>
 {
-    static NonDefaultFromJsonStruct from_json (json const&) noexcept
+    static NonDefaultFromJsonStruct from_json (json const& /*unused*/) noexcept
     {
         return {};
     }
 };
-}
+} // namespace nlohmann
 
 /////////////////////////////////////////////////////////////////////
 // for #1805
@@ -133,11 +134,34 @@ struct NotSerializableData
 };
 
 
+/////////////////////////////////////////////////////////////////////
+// for #2574
+/////////////////////////////////////////////////////////////////////
+
+struct NonDefaultConstructible
+{
+    explicit NonDefaultConstructible (int a) : x(a) { }
+    int x;
+};
+
+namespace nlohmann
+{
+template <>
+struct adl_serializer<NonDefaultConstructible>
+{
+    static NonDefaultConstructible from_json (json const& j)
+    {
+        return NonDefaultConstructible(j.get<int>());
+    }
+};
+} // namespace nlohmann
+
+
 TEST_CASE("regression tests 2")
 {
     SECTION("issue #1001 - Fix memory leak during parser callback")
     {
-        auto geojsonExample = R"(
+        const auto* geojsonExample = R"(
           { "type": "FeatureCollection",
             "features": [
               { "type": "Feature",
@@ -172,7 +196,7 @@ TEST_CASE("regression tests 2")
                ]
              })";
 
-        json::parser_callback_t cb = [&](int, json::parse_event_t event, json & parsed)
+        json::parser_callback_t cb = [&](int /*level*/, json::parse_event_t event, json & parsed)
         {
             // skip uninteresting events
             if (event == json::parse_event_t::value && !parsed.is_primitive())
@@ -288,7 +312,7 @@ TEST_CASE("regression tests 2")
             json dump_test;
             dump_test["1"] = std::string(length, -1);
 
-            std::string expected = "{\"1\":\"";
+            std::string expected = R"({"1":")";
             for (int i = 0; i < length; ++i)
             {
                 expected += "\\ufffd";
@@ -305,7 +329,7 @@ TEST_CASE("regression tests 2")
             json dump_test;
             dump_test["1"] = std::string(length, -2);
 
-            std::string expected = "{\"1\":\"";
+            std::string expected = R"({"1":")";
             for (int i = 0; i < length; ++i)
             {
                 expected += "\xEF\xBF\xBD";
@@ -318,29 +342,31 @@ TEST_CASE("regression tests 2")
         SECTION("test case in issue #1445")
         {
             nlohmann::json dump_test;
-            const int data[] =
+            const std::array<int, 108> data =
             {
-                109,  108,  103,  125,  -122, -53,  115,
-                18,   3,    0,    102,  19,   1,    15,
-                -110, 13,   -3,   -1,   -81,  32,   2,
-                0,    0,    0,    0,    0,    0,    0,
-                8,    0,    0,    0,    0,    0,    0,
-                0,    0,    0,    0,    0,    -80,  2,
-                0,    0,    96,   -118, 46,   -116, 46,
-                109,  -84,  -87,  108,  14,   109,  -24,
-                -83,  13,   -18,  -51,  -83,  -52,  -115,
-                14,   6,    32,   0,    0,    0,    0,
-                0,    0,    0,    0,    0,    0,    0,
-                64,   3,    0,    0,    0,    35,   -74,
-                -73,  55,   57,   -128, 0,    0,    0,
-                0,    0,    0,    0,    0,    0,    0,
-                0,    0,    33,   0,    0,    0,    -96,
-                -54,  -28,  -26
+                {
+                    109,  108,  103,  125,  -122, -53,  115,
+                    18,   3,    0,    102,  19,   1,    15,
+                    -110, 13,   -3,   -1,   -81,  32,   2,
+                    0,    0,    0,    0,    0,    0,    0,
+                    8,    0,    0,    0,    0,    0,    0,
+                    0,    0,    0,    0,    0,    -80,  2,
+                    0,    0,    96,   -118, 46,   -116, 46,
+                    109,  -84,  -87,  108,  14,   109,  -24,
+                    -83,  13,   -18,  -51,  -83,  -52,  -115,
+                    14,   6,    32,   0,    0,    0,    0,
+                    0,    0,    0,    0,    0,    0,    0,
+                    64,   3,    0,    0,    0,    35,   -74,
+                    -73,  55,   57,   -128, 0,    0,    0,
+                    0,    0,    0,    0,    0,    0,    0,
+                    0,    0,    33,   0,    0,    0,    -96,
+                    -54,  -28,  -26
+                }
             };
             std::string s;
-            for (unsigned i = 0; i < sizeof(data) / sizeof(int); i++)
+            for (int i : data)
             {
-                s += static_cast<char>(data[i]);
+                s += static_cast<char>(i);
             }
             dump_test["1"] = s;
             dump_test.dump(-1, ' ', true, nlohmann::json::error_handler_t::replace);
@@ -395,7 +421,7 @@ TEST_CASE("regression tests 2")
 
         SECTION("string array")
         {
-            const char input[] = { 'B', 0x00 };
+            const std::array<char, 2> input = {{ 'B', 0x00 }};
             json cbor = json::from_cbor(input, true, false);
             CHECK(cbor.is_discarded());
         }
@@ -430,8 +456,8 @@ TEST_CASE("regression tests 2")
 
     SECTION("issue #2067 - cannot serialize binary data to text JSON")
     {
-        const unsigned char data[] = {0x81, 0xA4, 0x64, 0x61, 0x74, 0x61, 0xC4, 0x0F, 0x33, 0x30, 0x30, 0x32, 0x33, 0x34, 0x30, 0x31, 0x30, 0x37, 0x30, 0x35, 0x30, 0x31, 0x30};
-        json j = json::from_msgpack(data, sizeof(data) / sizeof(data[0]));
+        const std::array<unsigned char, 23> data = {{0x81, 0xA4, 0x64, 0x61, 0x74, 0x61, 0xC4, 0x0F, 0x33, 0x30, 0x30, 0x32, 0x33, 0x34, 0x30, 0x31, 0x30, 0x37, 0x30, 0x35, 0x30, 0x31, 0x30}};
+        json j = json::from_msgpack(data.data(), data.size());
         CHECK_NOTHROW(
             j.dump(4,                              // Indent
                    ' ',                            // Indent char
@@ -498,4 +524,74 @@ TEST_CASE("regression tests 2")
         CHECK(j.dump() == "\"Hello, world!\"");
     }
 #endif
+
+    SECTION("issue #2574 - Deserialization to std::array, std::pair, and std::tuple with non-default constructable types fails")
+    {
+        SECTION("std::array")
+        {
+            {
+                json j = { 7, 4 };
+                auto arr = j.get<std::array<NonDefaultConstructible, 2>>();
+                CHECK(arr[0].x == 7);
+                CHECK(arr[1].x == 4);
+
+            }
+
+            {
+                json j = 7;
+                CHECK_THROWS_AS((j.get<std::array<NonDefaultConstructible, 1>>()), json::type_error);
+            }
+        }
+
+        SECTION("std::pair")
+        {
+            {
+                json j = { 3, 8 };
+                auto p = j.get<std::pair<NonDefaultConstructible, NonDefaultConstructible>>();
+                CHECK(p.first.x == 3);
+                CHECK(p.second.x == 8);
+            }
+
+            {
+                json j = { 4, 1 };
+                auto p = j.get<std::pair<int, NonDefaultConstructible>>();
+                CHECK(p.first == 4);
+                CHECK(p.second.x == 1);
+            }
+
+            {
+                json j = { 6, 7 };
+                auto p = j.get<std::pair<NonDefaultConstructible, int>>();
+                CHECK(p.first.x == 6);
+                CHECK(p.second == 7);
+            }
+
+            {
+                json j = 7;
+                CHECK_THROWS_AS((j.get<std::pair<NonDefaultConstructible, int>>()), json::type_error);
+            }
+        }
+
+        SECTION("std::tuple")
+        {
+            {
+                json j = { 9 };
+                auto t = j.get<std::tuple<NonDefaultConstructible>>();
+                CHECK(std::get<0>(t).x == 9);
+            }
+
+            {
+                json j = { 9, 8, 7 };
+                auto t = j.get<std::tuple<NonDefaultConstructible, int, NonDefaultConstructible>>();
+                CHECK(std::get<0>(t).x == 9);
+                CHECK(std::get<1>(t)   == 8);
+                CHECK(std::get<2>(t).x == 7);
+            }
+
+            {
+                json j = 7;
+                CHECK_THROWS_AS((j.get<std::tuple<NonDefaultConstructible>>()), json::type_error);
+            }
+        }
+    }
 }

test/src/unit-serialization.cpp

@@ -183,10 +183,10 @@ TEST_CASE("serialization")
             CHECK(to_string(j) == "\"" + expected + "\"");
         };
 
-        test("{\"x\":5,\"y\":6}", "{\\\"x\\\":5,\\\"y\\\":6}");
-        test("{\"x\":[10,null,null,null]}", "{\\\"x\\\":[10,null,null,null]}");
+        test(R"({"x":5,"y":6})", R"({\"x\":5,\"y\":6})");
+        test("{\"x\":[10,null,null,null]}", R"({\"x\":[10,null,null,null]})");
         test("test", "test");
-        test("[3,\"false\",false]", "[3,\\\"false\\\",false]");
+        test("[3,\"false\",false]", R"([3,\"false\",false])");
     }
 }
 

test/src/unit-testsuites.cpp

@@ -41,7 +41,7 @@ TEST_CASE("compliance tests from json.org")
 
     SECTION("expected failures")
     {
-        for (auto filename :
+        for (const auto* filename :
                 {
                     //TEST_DATA_DIRECTORY "/json_tests/fail1.json",
                     TEST_DATA_DIRECTORY "/json_tests/fail2.json",
@@ -90,7 +90,7 @@ TEST_CASE("compliance tests from json.org")
         // these tests fail above, because the parser does not end on EOF;
         // they succeed when the operator>> is used, because it does not
         // have this constraint
-        for (auto filename :
+        for (const auto* filename :
                 {
                     TEST_DATA_DIRECTORY "/json_tests/fail7.json",
                     TEST_DATA_DIRECTORY "/json_tests/fail8.json",
@@ -106,7 +106,7 @@ TEST_CASE("compliance tests from json.org")
 
     SECTION("expected passes")
     {
-        for (auto filename :
+        for (const auto* filename :
                 {
                     TEST_DATA_DIRECTORY "/json_tests/pass1.json",
                     TEST_DATA_DIRECTORY "/json_tests/pass2.json",
@@ -235,13 +235,9 @@ TEST_CASE("compliance tests from nativejson-benchmark")
                     5708990770823839524233143877797980545530986496.0);
 
         {
-            char n1e308[312];   // '1' followed by 308 '0'
+            std::string n1e308(312, '0');   // '1' followed by 308 '0'
             n1e308[0] = '[';
             n1e308[1] = '1';
-            for (int j = 2; j < 310; j++)
-            {
-                n1e308[j] = '0';
-            }
             n1e308[310] = ']';
             n1e308[311] = '\0';
             TEST_DOUBLE(n1e308, 1E308);
@@ -272,20 +268,20 @@ TEST_CASE("compliance tests from nativejson-benchmark")
 
         TEST_STRING("[\"\"]", "");
         TEST_STRING("[\"Hello\"]", "Hello");
-        TEST_STRING("[\"Hello\\nWorld\"]", "Hello\nWorld");
+        TEST_STRING(R"(["Hello\nWorld"])", "Hello\nWorld");
         //TEST_STRING("[\"Hello\\u0000World\"]", "Hello\0World");
-        TEST_STRING("[\"\\\"\\\\/\\b\\f\\n\\r\\t\"]", "\"\\/\b\f\n\r\t");
-        TEST_STRING("[\"\\u0024\"]", "\x24");         // Dollar sign U+0024
-        TEST_STRING("[\"\\u00A2\"]", "\xC2\xA2");     // Cents sign U+00A2
-        TEST_STRING("[\"\\u20AC\"]", "\xE2\x82\xAC"); // Euro sign U+20AC
-        TEST_STRING("[\"\\uD834\\uDD1E\"]", "\xF0\x9D\x84\x9E");  // G clef sign U+1D11E
+        TEST_STRING(R"(["\"\\/\b\f\n\r\t"])", "\"\\/\b\f\n\r\t");
+        TEST_STRING(R"(["\u0024"])", "$");         // Dollar sign U+0024
+        TEST_STRING(R"(["\u00A2"])", "\xC2\xA2");     // Cents sign U+00A2
+        TEST_STRING(R"(["\u20AC"])", "\xE2\x82\xAC"); // Euro sign U+20AC
+        TEST_STRING(R"(["\uD834\uDD1E"])", "\xF0\x9D\x84\x9E");  // G clef sign U+1D11E
     }
 
     SECTION("roundtrip")
     {
         // test cases are from https://github.com/miloyip/nativejson-benchmark/tree/master/test/data/roundtrip
 
-        for (auto filename :
+        for (const auto* filename :
                 {
                     TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip01.json",
                     TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip02.json",
@@ -422,9 +418,9 @@ TEST_CASE("json.org examples")
     }
 }
 
-TEST_CASE("RFC 7159 examples")
+TEST_CASE("RFC 8259 examples")
 {
-    // here, we list all JSON values from the RFC 7159 document
+    // here, we list all JSON values from the RFC 8259 document
 
     SECTION("7. Strings")
     {
@@ -441,7 +437,7 @@ TEST_CASE("RFC 7159 examples")
     SECTION("13 Examples")
     {
         {
-            auto json_contents = R"(
+            const auto* json_contents = R"(
             {
                  "Image": {
                      "Width":  800,
@@ -462,7 +458,7 @@ TEST_CASE("RFC 7159 examples")
         }
 
         {
-            auto json_contents = R"(
+            const auto* json_contents = R"(
                 [
                     {
                        "precision": "zip",
@@ -500,7 +496,7 @@ TEST_CASE("nst's JSONTestSuite")
     {
         SECTION("y")
         {
-            for (auto filename :
+            for (const auto* filename :
                     {
                         TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_array_arraysWithSpaces.json",
                         TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/y_array_empty-string.json",
@@ -610,7 +606,7 @@ TEST_CASE("nst's JSONTestSuite")
 
         SECTION("n")
         {
-            for (auto filename :
+            for (const auto* filename :
                     {
                         TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/n_array_1_true_without_comma.json",
                         TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/n_array_a_invalid_utf8.json",
@@ -822,7 +818,7 @@ TEST_CASE("nst's JSONTestSuite")
             // these tests fail above, because the parser does not end on EOF;
             // they succeed when the operator>> is used, because it does not
             // have this constraint
-            for (auto filename :
+            for (const auto* filename :
                     {
                         TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/n_array_comma_after_close.json",
                         TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/n_array_extra_close.json",
@@ -852,7 +848,7 @@ TEST_CASE("nst's JSONTestSuite")
 
         SECTION("i -> y")
         {
-            for (auto filename :
+            for (const auto* filename :
                     {
                         // we do not pose a limit on nesting
                         TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/i_structure_500_nested_arrays.json",
@@ -876,7 +872,7 @@ TEST_CASE("nst's JSONTestSuite")
         // numbers that overflow during parsing
         SECTION("i/y -> n (out of range)")
         {
-            for (auto filename :
+            for (const auto* filename :
                     {
                         TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/i_number_neg_int_huge_exp.json",
                         TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/i_number_pos_double_huge_exp.json",
@@ -895,7 +891,7 @@ TEST_CASE("nst's JSONTestSuite")
 
         SECTION("i -> n")
         {
-            for (auto filename :
+            for (const auto* filename :
                     {
                         TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/i_object_key_lone_2nd_surrogate.json",
                         TEST_DATA_DIRECTORY "/nst_json_testsuite/test_parsing/i_string_1st_surrogate_but_2nd_missing.json",
@@ -928,7 +924,7 @@ TEST_CASE("nst's JSONTestSuite (2)")
     {
         SECTION("y")
         {
-            for (auto filename :
+            for (const auto* filename :
                     {
                         TEST_DATA_DIRECTORY "/nst_json_testsuite2/test_parsing/y_array_arraysWithSpaces.json",
                         TEST_DATA_DIRECTORY "/nst_json_testsuite2/test_parsing/y_array_empty-string.json",
@@ -1039,7 +1035,7 @@ TEST_CASE("nst's JSONTestSuite (2)")
 
         SECTION("n")
         {
-            for (auto filename :
+            for (const auto* filename :
                     {
                         TEST_DATA_DIRECTORY "/nst_json_testsuite2/test_parsing/n_array_1_true_without_comma.json",
                         TEST_DATA_DIRECTORY "/nst_json_testsuite2/test_parsing/n_array_a_invalid_utf8.json",
@@ -1241,7 +1237,7 @@ TEST_CASE("nst's JSONTestSuite (2)")
 
         SECTION("n (previously overflowed)")
         {
-            for (auto filename :
+            for (const auto* filename :
                     {
                         TEST_DATA_DIRECTORY "/nst_json_testsuite2/test_parsing/n_structure_100000_opening_arrays.json",
                         TEST_DATA_DIRECTORY "/nst_json_testsuite2/test_parsing/n_structure_open_array_object.json"
@@ -1256,7 +1252,7 @@ TEST_CASE("nst's JSONTestSuite (2)")
 
         SECTION("i -> y")
         {
-            for (auto filename :
+            for (const auto* filename :
                     {
                         TEST_DATA_DIRECTORY "/nst_json_testsuite2/test_parsing/i_number_double_huge_neg_exp.json",
                         //TEST_DATA_DIRECTORY "/nst_json_testsuite2/test_parsing/i_number_huge_exp.json",
@@ -1307,7 +1303,7 @@ TEST_CASE("nst's JSONTestSuite (2)")
 
         SECTION("i -> n")
         {
-            for (auto filename :
+            for (const auto* filename :
                     {
                         //TEST_DATA_DIRECTORY "/nst_json_testsuite2/test_parsing/i_number_double_huge_neg_exp.json",
                         TEST_DATA_DIRECTORY "/nst_json_testsuite2/test_parsing/i_number_huge_exp.json",
@@ -1373,7 +1369,7 @@ std::string trim(const std::string& str)
     size_t last = str.find_last_not_of(' ');
     return str.substr(first, (last - first + 1));
 }
-}
+} // namespace
 
 TEST_CASE("Big List of Naughty Strings")
 {
@@ -1399,7 +1395,7 @@ TEST_CASE("Big List of Naughty Strings")
             line = trim(line);
 
             // remove trailing comma
-            line = line.substr(0, line.find_last_of(","));
+            line = line.substr(0, line.find_last_of(','));
 
             // discard lines without at least two characters (quotes)
             if (line.size() < 2)

test/src/unit-to_chars.cpp

@@ -38,7 +38,7 @@ using nlohmann::detail::dtoa_impl::reinterpret_bits;
 
 namespace
 {
-static float make_float(uint32_t sign_bit, uint32_t biased_exponent, uint32_t significand)
+float make_float(uint32_t sign_bit, uint32_t biased_exponent, uint32_t significand)
 {
     assert(sign_bit == 0 || sign_bit == 1);
     assert(biased_exponent <= 0xFF);
@@ -54,7 +54,7 @@ static float make_float(uint32_t sign_bit, uint32_t biased_exponent, uint32_t si
 }
 
 // ldexp -- convert f * 2^e to IEEE single precision
-static float make_float(uint64_t f, int e)
+float make_float(uint64_t f, int e)
 {
     constexpr uint64_t kHiddenBit               = 0x00800000;
     constexpr uint64_t kSignificandMask         = 0x007FFFFF;
@@ -90,7 +90,7 @@ static float make_float(uint64_t f, int e)
     return reinterpret_bits<float>(static_cast<uint32_t>(bits));
 }
 
-static double make_double(uint64_t sign_bit, uint64_t biased_exponent, uint64_t significand)
+double make_double(uint64_t sign_bit, uint64_t biased_exponent, uint64_t significand)
 {
     assert(sign_bit == 0 || sign_bit == 1);
     assert(biased_exponent <= 0x7FF);
@@ -106,7 +106,7 @@ static double make_double(uint64_t sign_bit, uint64_t biased_exponent, uint64_t
 }
 
 // ldexp -- convert f * 2^e to IEEE double precision
-static double make_double(uint64_t f, int e)
+double make_double(uint64_t f, int e)
 {
     constexpr uint64_t kHiddenBit               = 0x0010000000000000;
     constexpr uint64_t kSignificandMask         = 0x000FFFFFFFFFFFFF;
@@ -141,7 +141,7 @@ static double make_double(uint64_t f, int e)
     uint64_t bits = (f & kSignificandMask) | (biased_exponent << kPhysicalSignificandSize);
     return reinterpret_bits<double>(bits);
 }
-}
+} // namespace
 
 TEST_CASE("digit gen")
 {
@@ -153,12 +153,12 @@ TEST_CASE("digit gen")
             CAPTURE(digits)
             CAPTURE(expected_exponent)
 
-            char buf[32];
+            std::array<char, 32> buf{};
             int len = 0;
             int exponent = 0;
-            nlohmann::detail::dtoa_impl::grisu2(buf, len, exponent, number);
+            nlohmann::detail::dtoa_impl::grisu2(buf.data(), len, exponent, number);
 
-            CHECK(digits == std::string(buf, buf + len));
+            CHECK(digits == std::string(buf.data(), buf.data() + len));
             CHECK(expected_exponent == exponent);
         };
 
@@ -217,12 +217,12 @@ TEST_CASE("digit gen")
             CAPTURE(digits)
             CAPTURE(expected_exponent)
 
-            char buf[32];
+            std::array<char, 32> buf{};
             int len = 0;
             int exponent = 0;
-            nlohmann::detail::dtoa_impl::grisu2(buf, len, exponent, number);
+            nlohmann::detail::dtoa_impl::grisu2(buf.data(), len, exponent, number);
 
-            CHECK(digits == std::string(buf, buf + len));
+            CHECK(digits == std::string(buf.data(), buf.data() + len));
             CHECK(expected_exponent == exponent);
         };
 
@@ -360,7 +360,7 @@ TEST_CASE("formatting")
         auto check_float = [](float number, const std::string & expected)
         {
             std::array<char, 33> buf{};
-            char* end = nlohmann::detail::to_chars(buf.data(), buf.data() + 32, number);
+            char* end = nlohmann::detail::to_chars(buf.data(), buf.data() + 32, number); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
             std::string actual(buf.data(), end);
 
             CHECK(actual == expected);
@@ -420,7 +420,7 @@ TEST_CASE("formatting")
         auto check_double = [](double number, const std::string & expected)
         {
             std::array<char, 33> buf{};
-            char* end = nlohmann::detail::to_chars(buf.data(), buf.data() + 32, number);
+            char* end = nlohmann::detail::to_chars(buf.data(), buf.data() + 32, number); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
             std::string actual(buf.data(), end);
 
             CHECK(actual == expected);

test/src/unit-ubjson.cpp

@@ -51,42 +51,42 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool boolean(bool)
+    bool boolean(bool /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_integer(json::number_integer_t)
+    bool number_integer(json::number_integer_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_unsigned(json::number_unsigned_t)
+    bool number_unsigned(json::number_unsigned_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool number_float(json::number_float_t, const std::string&)
+    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool string(std::string&)
+    bool string(std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool binary(std::vector<std::uint8_t>&)
+    bool binary(std::vector<std::uint8_t>& /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool start_object(std::size_t)
+    bool start_object(std::size_t /*unused*/)
     {
         return events_left-- > 0;
     }
 
-    bool key(std::string&)
+    bool key(std::string& /*unused*/)
     {
         return events_left-- > 0;
     }
@@ -96,7 +96,7 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool start_array(std::size_t)
+    bool start_array(std::size_t /*unused*/)
     {
         return events_left-- > 0;
     }
@@ -106,7 +106,7 @@ class SaxCountdown
         return events_left-- > 0;
     }
 
-    bool parse_error(std::size_t, const std::string&, const json::exception&)
+    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/) // NOLINT(readability-convert-member-functions-to-static)
     {
         return false;
     }
@@ -114,7 +114,7 @@ class SaxCountdown
   private:
     int events_left = 0;
 };
-}
+} // namespace
 
 TEST_CASE("UBJSON")
 {
@@ -175,16 +175,16 @@ TEST_CASE("UBJSON")
                 {
                     std::vector<int64_t> numbers;
                     numbers.push_back((std::numeric_limits<int64_t>::min)());
-                    numbers.push_back(-1000000000000000000ll);
-                    numbers.push_back(-100000000000000000ll);
-                    numbers.push_back(-10000000000000000ll);
-                    numbers.push_back(-1000000000000000ll);
-                    numbers.push_back(-100000000000000ll);
-                    numbers.push_back(-10000000000000ll);
-                    numbers.push_back(-1000000000000ll);
-                    numbers.push_back(-100000000000ll);
-                    numbers.push_back(-10000000000ll);
-                    numbers.push_back(-2147483649ll);
+                    numbers.push_back(-1000000000000000000LL);
+                    numbers.push_back(-100000000000000000LL);
+                    numbers.push_back(-10000000000000000LL);
+                    numbers.push_back(-1000000000000000LL);
+                    numbers.push_back(-100000000000000LL);
+                    numbers.push_back(-10000000000000LL);
+                    numbers.push_back(-1000000000000LL);
+                    numbers.push_back(-100000000000LL);
+                    numbers.push_back(-10000000000LL);
+                    numbers.push_back(-2147483649LL);
                     for (auto i : numbers)
                     {
                         CAPTURE(i)
@@ -302,7 +302,7 @@ TEST_CASE("UBJSON")
 
                         // check individual bytes
                         CHECK(result[0] == 'I');
-                        int16_t restored = static_cast<int16_t>(((result[1] << 8) + result[2]));
+                        auto restored = static_cast<int16_t>(((result[1] << 8) + result[2]));
                         CHECK(restored == i);
 
                         // roundtrip
@@ -323,7 +323,7 @@ TEST_CASE("UBJSON")
 
                     // check individual bytes
                     CHECK(result[0] == 'I');
-                    int16_t restored = static_cast<int16_t>(((result[1] << 8) + result[2]));
+                    auto restored = static_cast<int16_t>(((result[1] << 8) + result[2]));
                     CHECK(restored == -9263);
 
                     // roundtrip
@@ -455,7 +455,7 @@ TEST_CASE("UBJSON")
 
                         // check individual bytes
                         CHECK(result[0] == 'I');
-                        uint16_t restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        auto restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
                         CHECK(restored == i);
 
                         // roundtrip
@@ -583,7 +583,7 @@ TEST_CASE("UBJSON")
 
                         // check individual bytes
                         CHECK(result[0] == 'i');
-                        uint8_t restored = static_cast<uint8_t>(result[1]);
+                        auto restored = static_cast<uint8_t>(result[1]);
                         CHECK(restored == i);
 
                         // roundtrip
@@ -616,7 +616,7 @@ TEST_CASE("UBJSON")
 
                         // check individual bytes
                         CHECK(result[0] == 'U');
-                        uint8_t restored = static_cast<uint8_t>(result[1]);
+                        auto restored = static_cast<uint8_t>(result[1]);
                         CHECK(restored == i);
 
                         // roundtrip
@@ -650,7 +650,7 @@ TEST_CASE("UBJSON")
 
                         // check individual bytes
                         CHECK(result[0] == 'I');
-                        uint16_t restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        auto restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
                         CHECK(restored == i);
 
                         // roundtrip
@@ -1535,7 +1535,7 @@ TEST_CASE("UBJSON")
             {
                 SECTION("size=false type=false")
                 {
-                    json j = json::parse("{\"a\": {\"b\": {\"c\": {}}}}");
+                    json j = json::parse(R"({"a": {"b": {"c": {}}}})");
                     std::vector<uint8_t> expected =
                     {
                         '{', 'i', 1, 'a', '{', 'i', 1, 'b', '{', 'i', 1, 'c', '{', '}', '}', '}', '}'
@@ -1550,7 +1550,7 @@ TEST_CASE("UBJSON")
 
                 SECTION("size=true type=false")
                 {
-                    json j = json::parse("{\"a\": {\"b\": {\"c\": {}}}}");
+                    json j = json::parse(R"({"a": {"b": {"c": {}}}})");
                     std::vector<uint8_t> expected =
                     {
                         '{', '#', 'i', 1, 'i', 1, 'a', '{', '#', 'i', 1, 'i', 1, 'b', '{', '#', 'i', 1, 'i', 1, 'c', '{', '#', 'i', 0
@@ -1565,7 +1565,7 @@ TEST_CASE("UBJSON")
 
                 SECTION("size=true type=true")
                 {
-                    json j = json::parse("{\"a\": {\"b\": {\"c\": {}}}}");
+                    json j = json::parse(R"({"a": {"b": {"c": {}}}})");
                     std::vector<uint8_t> expected =
                     {
                         '{', '$', '{', '#', 'i', 1, 'i', 1, 'a', '$', '{', '#', 'i', 1, 'i', 1, 'b', '$', '{', '#', 'i', 1, 'i', 1, 'c', '#', 'i', 0
@@ -1610,7 +1610,7 @@ TEST_CASE("UBJSON")
                 CHECK_THROWS_AS(_ = json::from_ubjson(v_ubjson), json::out_of_range&);
 
                 json j;
-                nlohmann::detail::json_sax_dom_callback_parser<json> scp(j, [](int, json::parse_event_t, const json&)
+                nlohmann::detail::json_sax_dom_callback_parser<json> scp(j, [](int /*unused*/, json::parse_event_t /*unused*/, const json& /*unused*/)
                 {
                     return true;
                 });
@@ -1624,7 +1624,7 @@ TEST_CASE("UBJSON")
                 CHECK_THROWS_AS(_ = json::from_ubjson(v_ubjson), json::out_of_range&);
 
                 json j;
-                nlohmann::detail::json_sax_dom_callback_parser<json> scp(j, [](int, json::parse_event_t, const json&)
+                nlohmann::detail::json_sax_dom_callback_parser<json> scp(j, [](int /*unused*/, json::parse_event_t /*unused*/, const json& /*unused*/)
                 {
                     return true;
                 });
@@ -2439,7 +2439,7 @@ TEST_CASE("all UBJSON first bytes")
             // check that parse_error.112 is only thrown if the
             // first byte is not in the supported set
             INFO_WITH_TEMP(e.what());
-            if (std::find(supported.begin(), supported.end(), byte) == supported.end())
+            if (supported.find(byte) == supported.end())
             {
                 CHECK(e.id == 112);
             }

test/src/unit-udt.cpp

@@ -32,10 +32,11 @@ SOFTWARE.
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 
-#include <array>
 #include <map>
+#include <memory>
 #include <string>
 #include <memory>
+#include <utility>
 
 namespace udt
 {
@@ -55,40 +56,40 @@ struct age
 struct name
 {
     std::string m_val;
-    name(const std::string rhs = "") : m_val(rhs) {}
+    name(std::string rhs = "") : m_val(std::move(rhs)) {}
 };
 
 struct address
 {
     std::string m_val;
-    address(const std::string rhs = "") : m_val(rhs) {}
+    address(std::string rhs = "") : m_val(std::move(rhs)) {}
 };
 
 struct person
 {
-    age m_age;
-    name m_name;
-    country m_country;
-    person() : m_age(), m_name(), m_country() {}
-    person(const age& a, const name& n, const country& c) : m_age(a), m_name(n), m_country(c) {}
+    age m_age{};
+    name m_name{};
+    country m_country{};
+    person() = default;
+    person(const age& a, name  n, const country& c) : m_age(a), m_name(std::move(n)), m_country(c) {}
 };
 
 struct contact
 {
-    person m_person;
-    address m_address;
-    contact() : m_person(), m_address() {}
-    contact(const person& p, const address& a) : m_person(p), m_address(a) {}
+    person m_person{};
+    address m_address{};
+    contact() = default;
+    contact(person p, address a) : m_person(std::move(p)), m_address(std::move(a)) {}
 };
 
 struct contact_book
 {
-    name m_book_name;
-    std::vector<contact> m_contacts;
-    contact_book() : m_book_name(), m_contacts() {}
-    contact_book(const name& n, const std::vector<contact>& c) : m_book_name(n), m_contacts(c) {}
+    name m_book_name{};
+    std::vector<contact> m_contacts{};
+    contact_book() = default;
+    contact_book(name n, std::vector<contact> c) : m_book_name(std::move(n)), m_contacts(std::move(c)) {}
 };
-}
+} // namespace udt
 
 // to_json methods
 namespace udt
@@ -178,7 +179,7 @@ static bool operator==(const contact_book& lhs, const contact_book& rhs)
     return std::tie(lhs.m_book_name, lhs.m_contacts) ==
            std::tie(rhs.m_book_name, rhs.m_contacts);
 }
-}
+} // namespace udt
 
 // from_json methods
 namespace udt
@@ -199,7 +200,7 @@ template <typename BasicJsonType>
 static void from_json(const BasicJsonType& j, country& c)
 {
     const auto str = j.template get<std::string>();
-    static const std::map<std::string, country> m =
+    const std::map<std::string, country> m =
     {
         {"中华人民共和国", country::china},
         {"France", country::france},
@@ -207,7 +208,7 @@ static void from_json(const BasicJsonType& j, country& c)
     };
 
     const auto it = m.find(str);
-    // TODO test exceptions
+    // TODO(nlohmann) test exceptions
     c = it->second;
 }
 
@@ -235,7 +236,7 @@ static void from_json(const nlohmann::json& j, contact_book& cb)
     cb.m_book_name = j["name"].get<name>();
     cb.m_contacts = j["contacts"].get<std::vector<contact>>();
 }
-}
+} // namespace udt
 
 TEST_CASE("basic usage" * doctest::test_suite("udt"))
 {
@@ -344,11 +345,11 @@ namespace udt
 {
 struct legacy_type
 {
-    std::string number;
-    legacy_type() : number() {}
-    legacy_type(const std::string& n) : number(n) {}
+    std::string number{};
+    legacy_type() = default;
+    legacy_type(std::string n) : number(std::move(n)) {}
 };
-}
+} // namespace udt
 
 namespace nlohmann
 {
@@ -375,7 +376,7 @@ struct adl_serializer<std::shared_ptr<T>>
         }
         else
         {
-            opt.reset(new T(j.get<T>()));
+            opt.reset(new T(j.get<T>())); // NOLINT(cppcoreguidelines-owning-memory)
         }
     }
 };
@@ -393,7 +394,7 @@ struct adl_serializer<udt::legacy_type>
         l.number = std::to_string(j.get<int>());
     }
 };
-}
+} // namespace nlohmann
 
 TEST_CASE("adl_serializer specialization" * doctest::test_suite("udt"))
 {
@@ -406,7 +407,7 @@ TEST_CASE("adl_serializer specialization" * doctest::test_suite("udt"))
             json j = optPerson;
             CHECK(j.is_null());
 
-            optPerson.reset(new udt::person{{42}, {"John Doe"}, udt::country::russia});
+            optPerson.reset(new udt::person{{42}, {"John Doe"}, udt::country::russia}); // NOLINT(cppcoreguidelines-owning-memory,modernize-make-shared)
             j = optPerson;
             CHECK_FALSE(j.is_null());
 
@@ -453,23 +454,23 @@ template <>
 struct adl_serializer<std::vector<float>>
 {
     using type = std::vector<float>;
-    static void to_json(json& j, const type&)
+    static void to_json(json& j, const type& /*type*/)
     {
         j = "hijacked!";
     }
 
-    static void from_json(const json&, type& opt)
+    static void from_json(const json& /*unnamed*/, type& opt)
     {
         opt = {42.0, 42.0, 42.0};
     }
 
     // preferred version
-    static type from_json(const json&)
+    static type from_json(const json& /*unnamed*/)
     {
         return {4.0, 5.0, 6.0};
     }
 };
-}
+} // namespace nlohmann
 
 TEST_CASE("even supported types can be specialized" * doctest::test_suite("udt"))
 {
@@ -504,13 +505,11 @@ struct adl_serializer<std::unique_ptr<T>>
         {
             return nullptr;
         }
-        else
-        {
-            return std::unique_ptr<T>(new T(j.get<T>()));
-        }
+
+        return std::unique_ptr<T>(new T(j.get<T>()));
     }
 };
-}
+} // namespace nlohmann
 
 TEST_CASE("Non-copyable types" * doctest::test_suite("udt"))
 {
@@ -521,7 +520,7 @@ TEST_CASE("Non-copyable types" * doctest::test_suite("udt"))
         json j = optPerson;
         CHECK(j.is_null());
 
-        optPerson.reset(new udt::person{{42}, {"John Doe"}, udt::country::russia});
+        optPerson.reset(new udt::person{{42}, {"John Doe"}, udt::country::russia}); // NOLINT(cppcoreguidelines-owning-memory,modernize-make-unique)
         j = optPerson;
         CHECK_FALSE(j.is_null());
 
@@ -566,8 +565,8 @@ struct pod_serializer
                    std::is_pod<U>::value && std::is_class<U>::value, int >::type = 0 >
     static void from_json(const  BasicJsonType& j, U& t)
     {
-        std::uint64_t value;
-        // TODO The following block is no longer relevant in this serializer, make another one that shows the issue
+        std::uint64_t value = 0;
+        // The following block is no longer relevant in this serializer, make another one that shows the issue
         // the problem arises only when one from_json method is defined without any constraint
         //
         // Why cannot we simply use: j.get<std::uint64_t>() ?
@@ -582,7 +581,7 @@ struct pod_serializer
         // calling get calls from_json, for now, we cannot do this in custom
         // serializers
         nlohmann::from_json(j, value);
-        auto bytes = static_cast<char*>(static_cast<void*>(&value));
+        auto* bytes = static_cast<char*>(static_cast<void*>(&value));
         std::memcpy(&t, bytes, sizeof(value));
     }
 
@@ -601,8 +600,8 @@ struct pod_serializer
                    std::is_pod<U>::value && std::is_class<U>::value, int >::type = 0 >
     static void to_json(BasicJsonType& j, const  T& t) noexcept
     {
-        auto bytes = static_cast< const unsigned char*>(static_cast<const void*>(&t));
-        std::uint64_t value;
+        const auto* bytes = static_cast< const unsigned char*>(static_cast<const void*>(&t));
+        std::uint64_t value = 0;
         std::memcpy(&value, bytes, sizeof(value));
         nlohmann::to_json(j, value);
     }
@@ -619,9 +618,9 @@ struct small_pod
 
 struct non_pod
 {
-    std::string s;
-    non_pod() : s() {}
-    non_pod(const std::string& S) : s(S) {}
+    std::string s{};
+    non_pod() = default;
+    non_pod(std::string S) : s(std::move(S)) {}
 };
 
 template <typename BasicJsonType>
@@ -651,7 +650,7 @@ static std::ostream& operator<<(std::ostream& os, small_pod l)
 {
     return os << "begin: " << l.begin << ", middle: " << l.middle << ", end: " << l.end;
 }
-}
+} // namespace udt
 
 TEST_CASE("custom serializer for pods" * doctest::test_suite("udt"))
 {
@@ -803,7 +802,7 @@ struct is_constructible_patched : std::false_type {};
 
 template <typename T>
 struct is_constructible_patched<T, decltype(void(json(std::declval<T>())))> : std::true_type {};
-}
+} // namespace
 
 TEST_CASE("an incomplete type does not trigger a compiler error in non-evaluated context" * doctest::test_suite("udt"))
 {
@@ -822,8 +821,8 @@ class Evil
     int m_i = 0;
 };
 
-void from_json(const json&, Evil&) {}
-}
+void from_json(const json& /*unused*/, Evil& /*unused*/) {}
+} // namespace
 
 TEST_CASE("Issue #924")
 {

test/src/unit-udt_macro.cpp

@@ -39,7 +39,7 @@ namespace persons
 class person_with_private_data
 {
   private:
-    std::string name = "";
+    std::string name{};
     int age = 0;
     json metadata = nullptr;
 
@@ -62,7 +62,7 @@ class person_with_private_data
 class person_without_private_data_1
 {
   public:
-    std::string name = "";
+    std::string name{};
     int age = 0;
     json metadata = nullptr;
 
@@ -84,7 +84,7 @@ class person_without_private_data_1
 class person_without_private_data_2
 {
   public:
-    std::string name = "";
+    std::string name{};
     int age = 0;
     json metadata = nullptr;
 

test/src/unit-unicode.cpp

@@ -168,7 +168,7 @@ void check_utf8string(bool success_expected, int byte1, int byte2 = -1, int byte
         CHECK_THROWS_AS(_ = json::parse(json_string), json::parse_error&);
     }
 }
-}
+} // namespace
 
 TEST_CASE("Unicode" * doctest::skip())
 {
@@ -1159,7 +1159,7 @@ TEST_CASE("Unicode" * doctest::skip())
 
         SECTION("check JSON Pointers")
         {
-            for (auto s : j)
+            for (const auto& s : j)
             {
                 // skip non-string JSON values
                 if (!s.is_string())
@@ -1176,13 +1176,13 @@ TEST_CASE("Unicode" * doctest::skip())
                 }
 
                 // JSON Pointers must begin with "/"
-                ptr = "/" + ptr;
+                ptr.insert(0, "/");
 
                 CHECK_NOTHROW(json::json_pointer("/" + ptr));
 
                 // check escape/unescape roundtrip
-                auto escaped = json::json_pointer::escape(ptr);
-                json::json_pointer::unescape(escaped);
+                auto escaped = nlohmann::detail::escape(ptr);
+                nlohmann::detail::unescape(escaped);
                 CHECK(escaped == ptr);
             }
         }
@@ -1256,7 +1256,7 @@ void roundtrip(bool success_expected, const std::string& s)
         CHECK_THROWS_AS(_ = json::parse(ps), json::parse_error&);
     }
 }
-}
+} // namespace
 
 TEST_CASE("Markus Kuhn's UTF-8 decoder capability and stress test")
 {

test/src/unit-user_defined_input.cpp

@@ -60,7 +60,7 @@ const char* begin(const MyContainer& c)
 
 const char* end(const MyContainer& c)
 {
-    return c.data + strlen(c.data);
+    return c.data + strlen(c.data); // NOLINT(cppcoreguidelines-pro-bounds-pointer-arithmetic)
 }
 
 TEST_CASE("Custom container non-member begin/end")
@@ -88,7 +88,7 @@ TEST_CASE("Custom container member begin/end")
 
         const char* end() const
         {
-            return data + strlen(data);
+            return data + strlen(data); // NOLINT(cppcoreguidelines-pro-bounds-pointer-arithmetic)
         }
     };
 
@@ -114,7 +114,7 @@ TEST_CASE("Custom iterator")
 
         MyIterator& operator++()
         {
-            ++ptr;
+            ++ptr; // NOLINT(cppcoreguidelines-pro-bounds-pointer-arithmetic)
             return *this;
         }
 
@@ -131,8 +131,15 @@ TEST_CASE("Custom iterator")
         const char* ptr;
     };
 
+    // avoid -Wunused-local-typedefs
+    CHECK(std::is_same<MyIterator::difference_type, std::size_t>::value);
+    CHECK(std::is_same<MyIterator::value_type, char>::value);
+    CHECK(std::is_same<MyIterator::pointer, const char*>::value);
+    CHECK(std::is_same<MyIterator::reference, const char&>::value);
+    CHECK(std::is_same<MyIterator::iterator_category, std::input_iterator_tag>::value);
+
     MyIterator begin{raw_data};
-    MyIterator end{raw_data + strlen(raw_data)};
+    MyIterator end{raw_data + strlen(raw_data)}; // NOLINT(cppcoreguidelines-pro-bounds-pointer-arithmetic)
 
     json as_json = json::parse(begin, end);
     CHECK(as_json.at(0) == 1);

test/src/unit-wstring.cpp

@@ -51,7 +51,7 @@ bool u32string_is_utf32()
 {
     return (std::u32string(U"💩") == std::u32string(U"\U0001F4A9"));
 }
-}
+} // namespace
 
 TEST_CASE("wide strings")
 {