Fix the CI failures that the first failing TU of each job hid

- unit-stream-bulk-scan: compute the claimed size without a condition;
  the tag-dispatched template was unused with a 64-bit std::size_t
  (-Wunused-template)
- unit-json_view: give failing_allocator the typedefs, rebind and
  members that GCC 4.8's std::map takes from the allocator directly
- clang-tidy hits in the tests from #5997: raw string literals
  (unit-json_view), redundant c_str() and a NOLINT for &text[0]
  (unit-locale-cpp), reserve() before a loop (unit-ordered_json), and a
  NOLINT for a return that a braced list would turn into an array
  (unit-regression1)

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

tests/src/unit-json_view.cpp

@@ -105,6 +105,20 @@ template<typename T>
 struct failing_allocator
 {
     using value_type = T;
+    // GCC 4.8's std::map takes these from the allocator instead of from
+    // std::allocator_traits
+    using pointer = T*;
+    using const_pointer = const T*;
+    using reference = T&;
+    using const_reference = const T&;
+    using size_type = std::size_t;
+    using difference_type = std::ptrdiff_t;
+
+    template<typename U>
+    struct rebind
+    {
+        using other = failing_allocator<U>;
+    };
 
     failing_allocator() = default;
 
@@ -118,6 +132,26 @@ struct failing_allocator
 
     void deallocate(T* /*p*/, std::size_t /*n*/) noexcept {} // NOLINT(readability-convert-member-functions-to-static)
 
+    // GCC 4.8's std::map calls these on the allocator directly instead of
+    // going through std::allocator_traits
+    std::size_t max_size() const noexcept // NOLINT(readability-convert-member-functions-to-static)
+    {
+        return (std::numeric_limits<std::size_t>::max)() / sizeof(T);
+    }
+
+    template<typename U, typename... Args>
+    void construct(U* p, Args&& ... args) // NOLINT(readability-convert-member-functions-to-static)
+    {
+        ::new (static_cast<void*>(p)) U(std::forward<Args>(args)...);
+    }
+
+    template<typename U>
+    void destroy(U* p) noexcept // NOLINT(readability-convert-member-functions-to-static)
+    {
+        static_cast<void>(p); // unused for trivially destructible types
+        p->~U();
+    }
+
     template<typename U>
     bool operator==(const failing_allocator<U>& /*other*/) const noexcept
     {
@@ -270,7 +304,7 @@ TEST_CASE("json_view")
                     "\"", "\"abc", "\"\\x\"", "\"\\u12\"", "\"\\ud800\"", "\"\\udc00\"", "\"\x01\"", "\"\xff\"", "\"\xc3\"", "[1]x", "/", "/*", "[\n  1,\n  x\n]", // NOLINT(modernize-raw-string-literal)
                     "1e400", "-1e400", "[1.7976931348623159e308]", "{\"a\":\n{\"b\": [1, 2,\n 3 x]}}",
                     // (an error after every kind of value: the error is found by replaying the parser)
-                    "[null, true, -1, 1, 1.5, \"s\", {\"a\": 1} 2]", "{\"a\": null, \"b\": -1, \"c\": 1.5, \"d\": \"s\", \"e\": {}, 1}"
+                    R"([null, true, -1, 1, 1.5, "s", {"a": 1} 2])", R"({"a": null, "b": -1, "c": 1.5, "d": "s", "e": {}, 1})"
                 })
         {
             CAPTURE(text)

tests/src/unit-locale-cpp.cpp

@@ -525,7 +525,7 @@ struct locale_switching_token
         {
             switched = std::setlocale(LC_NUMERIC, switch_to.c_str()) != nullptr;
         }
-        return &text[0];
+        return &text[0]; // NOLINT(readability-container-data-pointer): std::string::data() is const before C++17
     }
 
     std::string text;
@@ -647,7 +647,7 @@ TEST_CASE("convert_float_locale_aware")
 
             // "C" -> comma locale: strtod stops at the '.', so the conversion is repeated
             {
-                locale_switching_token token("1.5", comma_locale.c_str());
+                locale_switching_token token("1.5", comma_locale);
                 double value = 0;
                 nlohmann::detail::convert_float_locale_aware(token, 1, value);
                 if (token.switched)
@@ -660,7 +660,7 @@ TEST_CASE("convert_float_locale_aware")
             // the same for the other floating-point types
             REQUIRE(std::setlocale(LC_NUMERIC, "C") != nullptr);
             {
-                locale_switching_token token("2.25", comma_locale.c_str());
+                locale_switching_token token("2.25", comma_locale);
                 float value = 0;
                 nlohmann::detail::convert_float_locale_aware(token, 1, value);
                 if (token.switched)
@@ -670,7 +670,7 @@ TEST_CASE("convert_float_locale_aware")
             }
             REQUIRE(std::setlocale(LC_NUMERIC, "C") != nullptr);
             {
-                locale_switching_token token("2.25", comma_locale.c_str());
+                locale_switching_token token("2.25", comma_locale);
                 long double value = 0;
                 nlohmann::detail::convert_float_locale_aware(token, 1, value);
                 if (token.switched)

tests/src/unit-ordered_json.cpp

@@ -541,6 +541,7 @@ TEST_CASE("object_key_index")
         };
 
         std::vector<std::size_t> hashes;
+        hashes.reserve(initial);
         for (std::size_t i = 0; i < initial; ++i)
         {
             hashes.push_back(hash_of(i));

tests/src/unit-regression1.cpp

@@ -1533,7 +1533,7 @@ TEST_CASE("regression tests 1")
         {
             my_json::object_t top = orig.get_ref<const my_json::object_t&>();
             top.at("x") = my_json::parse(R"({"a":{"b":1},"n":null,"arr":[10,20],"objs":[{"m":5},{"m":6}]})");
-            return my_json(std::move(top));
+            return my_json(std::move(top)); // NOLINT(modernize-return-braced-init-list): {top} would be an array
         };
 
         SECTION("existing members")

tests/src/unit-stream-bulk-scan.cpp

@@ -121,19 +121,6 @@ class oversized_get_area_streambuf : public std::streambuf
     std::array<char, 8> m_data{{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'}};
 };
 
-// the size the oversized_get_area_streambuf claims: 3 GiB with a 64-bit
-// std::size_t, else 0 to skip the test (tag dispatch, as a constant condition
-// triggers MSVC's C4127)
-template<std::size_t SizeOfSizeT>
-std::size_t oversized_get_area_size(std::integral_constant<std::size_t, SizeOfSizeT> /*unused*/)
-{
-    return 0;
-}
-
-std::size_t oversized_get_area_size(std::integral_constant<std::size_t, 8> /*unused*/)
-{
-    return std::size_t{3} << 30u;
-}
 #endif
 
 // how a test reads from the stream
@@ -480,7 +467,9 @@ TEST_CASE("parsing from a std::istream scans the get area in bulk")
     SECTION("skipping more characters than gbump() takes at once")
     {
         // gbump() takes an int, but a get area can be larger
-        const std::size_t claimed = oversized_get_area_size(std::integral_constant<std::size_t, sizeof(std::size_t)>());
+        // 3 GiB with a 64-bit std::size_t, else 0 (computed without a
+        // condition, which would trigger MSVC's C4127)
+        const std::size_t claimed = (std::size_t{3} << 30u) * (sizeof(std::size_t) / 8);
         oversized_get_area_streambuf buf(claimed);
         if (claimed == 0 || static_cast<std::size_t>(buf.in_avail()) != claimed)
         {