Keep the Qt keyword macros in the test from failing -Wunused-macros

Clang (-Werror) rejected the macros that the test defines but the library
must not use, and clang-tidy asked for parentheses around the arguments
of the Q_FOREACH imitation, where the variable is a declaration.

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

docs/mkdocs/docs/community/quality_assurance.md

@@ -135,6 +135,9 @@ Note: Some modern features (like C++20 ranges or filesystem support) may be disa
   headers are included.
 - [x] On Windows, the library is compiled with `<Windows.h>` being included to detect and avoid common bugs (see
   [`unit-windows_h.cpp`](https://github.com/nlohmann/json/blob/develop/tests/src/unit-windows_h.cpp)).
+- [x] The library is compiled with Qt's keyword macros (`slots`, `signals`, `emit`, `foreach`, `forever`) being defined
+  to make sure it does not use them as identifiers (see
+  [`unit-qt_keywords.cpp`](https://github.com/nlohmann/json/blob/develop/tests/src/unit-qt_keywords.cpp)).
 - [x] The library is compiled with exceptions disabled to support alternative means of error handling.
 
 ## Stable public API

include/nlohmann/detail/json_pointer.hpp

@@ -525,7 +525,7 @@ class json_pointer
             {}
         };
 
-        std::vector<slot> slots;
+        std::vector<slot> table;
         std::size_t used = 0;
 
         static std::size_t hash_of(std::size_t parent, const string_t& token) noexcept
@@ -540,19 +540,19 @@ class json_pointer
 
         void grow()
         {
-            std::vector<slot> old(slots.size() * 2);
+            std::vector<slot> old(table.size() * 2);
-            old.swap(slots);
+            old.swap(table);
-            const std::size_t mask = slots.size() - 1;
+            const std::size_t mask = table.size() - 1;
             for (const auto& s : old)
             {
                 if (s.token != nullptr)
                 {
                     std::size_t i = s.hash & mask;
-                    while (slots[i].token != nullptr)
+                    while (table[i].token != nullptr)
                     {
                         i = (i + 1) & mask;
                     }
-                    slots[i] = s;
+                    table[i] = s;
                 }
             }
         }
@@ -565,7 +565,7 @@ class json_pointer
 
         // start with the empty prefix only
         prefix_tree()
-            : slots(16)
+            : table(16)
             , parent(1, 0)
             , is_array(1, false)
         {}
@@ -575,20 +575,20 @@ class json_pointer
         std::size_t add_child(std::size_t id, const string_t& reference_token)
         {
             const std::size_t hash = hash_of(id, reference_token);
-            const std::size_t mask = slots.size() - 1;
+            const std::size_t mask = table.size() - 1;
             std::size_t i = hash & mask;
-            while (slots[i].token != nullptr)
+            while (table[i].token != nullptr)
             {
-                if (slots[i].hash == hash && slots[i].parent == id && *slots[i].token == reference_token)
+                if (table[i].hash == hash && table[i].parent == id && *table[i].token == reference_token)
                 {
-                    return slots[i].id;
+                    return table[i].id;
                 }
                 i = (i + 1) & mask;
             }
 
             // new prefix
             const std::size_t child = parent.size();
-            slots[i] = slot(hash, id, &reference_token, child);
+            table[i] = slot(hash, id, &reference_token, child);
             if (reference_token == "0")
             {
                 is_array[id] = true;
@@ -597,7 +597,7 @@ class json_pointer
             is_array.push_back(false);
 
             // keep the load factor below 1/2
-            if (++used * 2 > slots.size())
+            if (++used * 2 > table.size())
             {
                 grow();
             }

single_include/nlohmann/json.hpp

@@ -21497,7 +21497,7 @@ class json_pointer
             {}
         };
 
-        std::vector<slot> slots;
+        std::vector<slot> table;
         std::size_t used = 0;
 
         static std::size_t hash_of(std::size_t parent, const string_t& token) noexcept
@@ -21512,19 +21512,19 @@ class json_pointer
 
         void grow()
         {
-            std::vector<slot> old(slots.size() * 2);
+            std::vector<slot> old(table.size() * 2);
-            old.swap(slots);
+            old.swap(table);
-            const std::size_t mask = slots.size() - 1;
+            const std::size_t mask = table.size() - 1;
             for (const auto& s : old)
             {
                 if (s.token != nullptr)
                 {
                     std::size_t i = s.hash & mask;
-                    while (slots[i].token != nullptr)
+                    while (table[i].token != nullptr)
                     {
                         i = (i + 1) & mask;
                     }
-                    slots[i] = s;
+                    table[i] = s;
                 }
             }
         }
@@ -21537,7 +21537,7 @@ class json_pointer
 
         // start with the empty prefix only
         prefix_tree()
-            : slots(16)
+            : table(16)
             , parent(1, 0)
             , is_array(1, false)
         {}
@@ -21547,20 +21547,20 @@ class json_pointer
         std::size_t add_child(std::size_t id, const string_t& reference_token)
         {
             const std::size_t hash = hash_of(id, reference_token);
-            const std::size_t mask = slots.size() - 1;
+            const std::size_t mask = table.size() - 1;
             std::size_t i = hash & mask;
-            while (slots[i].token != nullptr)
+            while (table[i].token != nullptr)
             {
-                if (slots[i].hash == hash && slots[i].parent == id && *slots[i].token == reference_token)
+                if (table[i].hash == hash && table[i].parent == id && *table[i].token == reference_token)
                 {
-                    return slots[i].id;
+                    return table[i].id;
                 }
                 i = (i + 1) & mask;
             }
 
             // new prefix
             const std::size_t child = parent.size();
-            slots[i] = slot(hash, id, &reference_token, child);
+            table[i] = slot(hash, id, &reference_token, child);
             if (reference_token == "0")
             {
                 is_array[id] = true;
@@ -21569,7 +21569,7 @@ class json_pointer
             is_array.push_back(false);
 
             // keep the load factor below 1/2
-            if (++used * 2 > slots.size())
+            if (++used * 2 > table.size())
             {
                 grow();
             }

tests/benchmarks/README.md

@@ -16,15 +16,6 @@ Micro-benchmarks for parsing, serialization and the binary formats, written with
 | `FromBinaryBuffer`, `FromBinaryFile` | read CBOR, MessagePack, UBJSON, BJData and BSON from a buffer or a `FILE*` |
 | `FromBinaryShape` | read deeply nested, container-heavy and scalar-heavy documents in every binary format |
 | `FromCborChunkedString` | read CBOR strings split into indefinite-length chunks |
-| `SaxParse` | parse with a SAX handler that only counts events, so no values are built |
-| `Copy`, `CopyAssign`, `CopyRing` | copy a parsed document and destroy a copy, both timed: a temporary copy, an assignment over an earlier copy, and replacing the oldest of eight live copies |
-| `CopyOnly`, `DestroyOnly` | only the copy or only the destruction, the other half untimed; a fast destructor can leave work to the next allocations, so these tell the halves apart but do not compare versions |
-| `Equal`, `Iterate` | compare a parsed document with a copy, or visit every value with range-based `for` loops |
-| `Flatten`, `FlattenOrdered`, `Unflatten` | `flatten()` for `json` and `ordered_json`, and `unflatten()` |
-| `Diff`, `Patch` | `diff()` against the document with every eighth scalar changed, and applying that patch |
-| `JsonPointerParse`, `JsonPointerToString`, `JsonPointerAt`, `JsonPointerContains` | the JSON pointers of every scalar in a document: parse them from strings, turn them back into strings, look them up with `at()` and `contains()` |
-| `GetVectorInt`, `GetVectorDouble`, `GetMap` | `get<std::vector<std::int64_t>>()`, `get<std::vector<double>>()` and `get<std::map<std::string, json>>()` on large arrays and a large flat object |
-| `ToJsonStrings` | create a `json` array from a `std::vector` of 100,000 strings, copied or moved, and destroy it again |
 
 The input files are those of [nativejson-benchmark](https://github.com/miloyip/nativejson-benchmark) (`canada`,
 `citm_catalog`, `twitter`), a large `jeopardy` file, and number-heavy files (`floats`, `signed_ints`, ...).

tests/benchmarks/src/benchmarks.cpp

@@ -8,14 +8,11 @@
 
 #include <benchmark/benchmark.h>
 #include <nlohmann/json.hpp>
-#include <array>
-#include <cstdint>
-#include <deque>
 #include <fstream>
-#include <map>
+#include <array>
+#include <deque>
 #include <numeric>
 #include <set>
-#include <string>
 #include <vector>
 #include <test_data.hpp>
 
@@ -627,584 +624,6 @@ static void FromCborChunkedString(benchmark::State& state, const std::size_t chu
 
 BENCHMARK_CAPTURE(FromCborChunkedString, 10000 chunks, 10000);
 
-//////////////////////////////////////////////////////////////////////////////
-// SAX-parse JSON from string
-//
-// sax_parse() with a handler that does next to nothing runs the lexer and
-// parser without building values, so the gap to ParseString above is the cost
-// of building the DOM.
-//////////////////////////////////////////////////////////////////////////////
-
-static std::string read_file(const char* filename)
-{
-    std::ifstream f(filename);
-    return std::string((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
-}
-
-static json load_json(const char* filename)
-{
-    return json::parse(read_file(filename));
-}
-
-/// SAX handler that only counts the events, so that the handler costs next to nothing
-class counting_sax : public nlohmann::json_sax<json>
-{
-  public:
-    std::size_t events = 0;
-
-    bool null() override
-    {
-        return count();
-    }
-    bool boolean(bool /*val*/) override
-    {
-        return count();
-    }
-    bool number_integer(number_integer_t /*val*/) override
-    {
-        return count();
-    }
-    bool number_unsigned(number_unsigned_t /*val*/) override
-    {
-        return count();
-    }
-    bool number_float(number_float_t /*val*/, const string_t& /*s*/) override
-    {
-        return count();
-    }
-    bool string(string_t& /*val*/) override
-    {
-        return count();
-    }
-    bool binary(binary_t& /*val*/) override
-    {
-        return count();
-    }
-    bool start_object(std::size_t /*elements*/) override
-    {
-        return count();
-    }
-    bool key(string_t& /*val*/) override
-    {
-        return count();
-    }
-    bool end_object() override
-    {
-        return count();
-    }
-    bool start_array(std::size_t /*elements*/) override
-    {
-        return count();
-    }
-    bool end_array() override
-    {
-        return count();
-    }
-    bool parse_error(std::size_t /*position*/, const std::string& /*last_token*/, const json::exception& /*ex*/) override
-    {
-        return false;
-    }
-
-  private:
-    bool count()
-    {
-        ++events;
-        return true;
-    }
-};
-
-static void SaxParse(benchmark::State& state, const char* filename)
-{
-    const std::string str = read_file(filename);
-
-    for (auto _ : state)
-    {
-        counting_sax sax;
-        bool result = json::sax_parse(str, &sax);
-        benchmark::DoNotOptimize(result);
-        benchmark::DoNotOptimize(sax.events);
-    }
-
-    state.SetBytesProcessed(state.iterations() * str.size());
-}
-BENCHMARK_CAPTURE(SaxParse, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(SaxParse, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(SaxParse, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-//////////////////////////////////////////////////////////////////////////////
-// work with values: copy, destroy, compare, iterate
-//
-// The parsed test files stand in for a document an application keeps around.
-// Each benchmark times one whole-document operation; setup and cleanup run
-// outside the timed section.
-//
-// A copy is always destroyed again, and how a document is freed shapes the
-// heap the next copy allocates from: a destructor that frees quickly can leave
-// work to the allocator's next calls. Copy, CopyAssign and CopyRing therefore
-// time the copy together with the destruction of a copy; CopyOnly and
-// DestroyOnly time one half each and are meant for telling the halves apart,
-// not for comparing versions.
-//////////////////////////////////////////////////////////////////////////////
-
-/// copy a document and destroy the copy again, as a temporary copy is used
-static void Copy(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename);
-
-    for (auto _ : state)
-    {
-        json copy = j;
-        benchmark::DoNotOptimize(copy);
-    }
-}
-BENCHMARK_CAPTURE(Copy, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(Copy, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(Copy, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-/// copy-assign a document over an earlier copy of it, which is freed in the process
-static void CopyAssign(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename);
-    json target = j;
-
-    for (auto _ : state)
-    {
-        target = j;
-        benchmark::DoNotOptimize(target);
-    }
-}
-BENCHMARK_CAPTURE(CopyAssign, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(CopyAssign, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(CopyAssign, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-/// keep eight copies alive and replace the oldest one, as a cache or an undo
-/// history does, so that the copy is not made from memory just freed by an
-/// identical document
-static void CopyRing(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename);
-    std::vector<json> ring(8, j);
-    std::size_t oldest = 0;
-
-    for (auto _ : state)
-    {
-        ring[oldest] = j;
-        benchmark::DoNotOptimize(ring[oldest]);
-        oldest = (oldest + 1) % ring.size();
-    }
-}
-BENCHMARK_CAPTURE(CopyRing, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(CopyRing, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(CopyRing, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-/// only the copy; the copy is destroyed with the timer paused (diagnostic)
-static void CopyOnly(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename);
-
-    for (auto _ : state)
-    {
-        auto* copy = new json(j);
-
-        state.PauseTiming();
-        delete copy;
-        state.ResumeTiming();
-    }
-}
-BENCHMARK_CAPTURE(CopyOnly, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(CopyOnly, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(CopyOnly, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-/// only the destruction; the copy is made with the timer paused (diagnostic)
-static void DestroyOnly(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename);
-
-    for (auto _ : state)
-    {
-        state.PauseTiming();
-        auto* copy = new json(j);
-        state.ResumeTiming();
-
-        delete copy;
-    }
-}
-BENCHMARK_CAPTURE(DestroyOnly, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(DestroyOnly, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(DestroyOnly, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-static void Equal(benchmark::State& state, const char* filename)
-{
-    // two separate values, so that the comparison cannot stop at identical addresses
-    const json j = load_json(filename);
-    const json copy = j;
-
-    for (auto _ : state)
-    {
-        bool result = (j == copy);
-        benchmark::DoNotOptimize(result);
-    }
-}
-BENCHMARK_CAPTURE(Equal, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(Equal, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(Equal, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-/// visit every value with range-based for loops, as client code walks a document
-static std::size_t count_values(const json& j)
-{
-    std::size_t result = 1;
-    if (j.is_structured())
-    {
-        for (const auto& element : j)
-        {
-            result += count_values(element);
-        }
-    }
-    return result;
-}
-
-static void Iterate(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename);
-
-    for (auto _ : state)
-    {
-        std::size_t result = count_values(j);
-        benchmark::DoNotOptimize(result);
-    }
-
-    state.SetItemsProcessed(state.iterations() * static_cast<std::int64_t>(count_values(j)));
-}
-BENCHMARK_CAPTURE(Iterate, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(Iterate, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(Iterate, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-//////////////////////////////////////////////////////////////////////////////
-// flatten and unflatten
-//////////////////////////////////////////////////////////////////////////////
-
-static void Flatten(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename);
-
-    for (auto _ : state)
-    {
-        json flat = j.flatten();
-        benchmark::DoNotOptimize(flat);
-    }
-}
-BENCHMARK_CAPTURE(Flatten, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(Flatten, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(Flatten, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-// ordered_json objects look keys up linearly, which flatten() used to do for
-// every value; canada (330,000 values in one flat object) is left out, as it
-// would take minutes with such versions
-static void FlattenOrdered(benchmark::State& state, const char* filename)
-{
-    const nlohmann::ordered_json j = nlohmann::ordered_json::parse(read_file(filename));
-
-    for (auto _ : state)
-    {
-        nlohmann::ordered_json flat = j.flatten();
-        benchmark::DoNotOptimize(flat);
-    }
-}
-BENCHMARK_CAPTURE(FlattenOrdered, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(FlattenOrdered, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-static void Unflatten(benchmark::State& state, const char* filename)
-{
-    const json flat = load_json(filename).flatten();
-
-    for (auto _ : state)
-    {
-        json j = flat.unflatten();
-        benchmark::DoNotOptimize(j);
-    }
-}
-BENCHMARK_CAPTURE(Unflatten, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(Unflatten, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(Unflatten, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-//////////////////////////////////////////////////////////////////////////////
-// diff and patch
-//
-// The target is the document with every eighth scalar changed, so the patch
-// has one "replace" operation per changed value and the structure stays the
-// same.
-//////////////////////////////////////////////////////////////////////////////
-
-static void change_every_eighth_scalar(json& j, std::size_t& counter)
-{
-    if (j.is_structured())
-    {
-        for (auto& element : j)
-        {
-            change_every_eighth_scalar(element, counter);
-        }
-        return;
-    }
-
-    if (++counter % 8 != 0)
-    {
-        return;
-    }
-
-    switch (j.type())
-    {
-        case json::value_t::number_integer:
-            j = j.get<json::number_integer_t>() + 1;
-            break;
-        case json::value_t::number_unsigned:
-            j = j.get<json::number_unsigned_t>() + 1;
-            break;
-        case json::value_t::number_float:
-            j = j.get<json::number_float_t>() + 0.5;
-            break;
-        case json::value_t::string:
-            j = j.get<std::string>() + "!";
-            break;
-        case json::value_t::boolean:
-            j = !j.get<bool>();
-            break;
-        case json::value_t::null:
-        case json::value_t::object:
-        case json::value_t::array:
-        case json::value_t::binary:
-        case json::value_t::discarded:
-        default:
-            j = 0;
-            break;
-    }
-}
-
-static json changed_copy(const json& j)
-{
-    json result = j;
-    std::size_t counter = 0;
-    change_every_eighth_scalar(result, counter);
-    return result;
-}
-
-static void Diff(benchmark::State& state, const char* filename)
-{
-    const json source = load_json(filename);
-    const json target = changed_copy(source);
-
-    for (auto _ : state)
-    {
-        json patch = json::diff(source, target);
-        benchmark::DoNotOptimize(patch);
-    }
-
-    state.SetItemsProcessed(state.iterations() * static_cast<std::int64_t>(json::diff(source, target).size()));
-}
-BENCHMARK_CAPTURE(Diff, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(Diff, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(Diff, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-static void Patch(benchmark::State& state, const char* filename)
-{
-    const json source = load_json(filename);
-    const json patch = json::diff(source, changed_copy(source));
-
-    for (auto _ : state)
-    {
-        json result = source.patch(patch);
-        benchmark::DoNotOptimize(result);
-    }
-
-    state.SetItemsProcessed(state.iterations() * static_cast<std::int64_t>(patch.size()));
-}
-BENCHMARK_CAPTURE(Patch, canada,       TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
-BENCHMARK_CAPTURE(Patch, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(Patch, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-//////////////////////////////////////////////////////////////////////////////
-// JSON Pointer
-//
-// The pointers are those of every scalar in the document, i.e., the keys of
-// its flattened form.
-//////////////////////////////////////////////////////////////////////////////
-
-static std::vector<std::string> pointer_strings(const json& j)
-{
-    std::vector<std::string> result;
-    const json flat = j.flatten();
-    result.reserve(flat.size());
-    for (auto it = flat.begin(); it != flat.end(); ++it)
-    {
-        result.push_back(it.key());
-    }
-    return result;
-}
-
-static std::vector<json::json_pointer> pointers(const json& j)
-{
-    const std::vector<std::string> strings = pointer_strings(j);
-    std::vector<json::json_pointer> result;
-    result.reserve(strings.size());
-    for (const auto& s : strings)
-    {
-        result.emplace_back(s);
-    }
-    return result;
-}
-
-static void JsonPointerParse(benchmark::State& state, const char* filename)
-{
-    const std::vector<std::string> strings = pointer_strings(load_json(filename));
-
-    for (auto _ : state)
-    {
-        for (const auto& s : strings)
-        {
-            json::json_pointer ptr(s);
-            benchmark::DoNotOptimize(ptr);
-        }
-    }
-
-    state.SetItemsProcessed(state.iterations() * static_cast<std::int64_t>(strings.size()));
-}
-BENCHMARK_CAPTURE(JsonPointerParse, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(JsonPointerParse, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-static void JsonPointerToString(benchmark::State& state, const char* filename)
-{
-    const std::vector<json::json_pointer> ptrs = pointers(load_json(filename));
-
-    for (auto _ : state)
-    {
-        for (const auto& ptr : ptrs)
-        {
-            std::string s = ptr.to_string();
-            benchmark::DoNotOptimize(s);
-        }
-    }
-
-    state.SetItemsProcessed(state.iterations() * static_cast<std::int64_t>(ptrs.size()));
-}
-BENCHMARK_CAPTURE(JsonPointerToString, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(JsonPointerToString, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-static void JsonPointerAt(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename);
-    const std::vector<json::json_pointer> ptrs = pointers(j);
-
-    for (auto _ : state)
-    {
-        for (const auto& ptr : ptrs)
-        {
-            const json& value = j.at(ptr);
-            benchmark::DoNotOptimize(&value);
-        }
-    }
-
-    state.SetItemsProcessed(state.iterations() * static_cast<std::int64_t>(ptrs.size()));
-}
-BENCHMARK_CAPTURE(JsonPointerAt, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(JsonPointerAt, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-static void JsonPointerContains(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename);
-    const std::vector<json::json_pointer> ptrs = pointers(j);
-
-    for (auto _ : state)
-    {
-        for (const auto& ptr : ptrs)
-        {
-            bool result = j.contains(ptr);
-            benchmark::DoNotOptimize(result);
-        }
-    }
-
-    state.SetItemsProcessed(state.iterations() * static_cast<std::int64_t>(ptrs.size()));
-}
-BENCHMARK_CAPTURE(JsonPointerContains, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-BENCHMARK_CAPTURE(JsonPointerContains, twitter,      TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
-
-//////////////////////////////////////////////////////////////////////////////
-// conversions from and to C++ containers
-//////////////////////////////////////////////////////////////////////////////
-
-static void GetVectorInt(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename);
-
-    for (auto _ : state)
-    {
-        auto v = j.get<std::vector<std::int64_t>>();
-        benchmark::DoNotOptimize(v);
-    }
-
-    state.SetItemsProcessed(state.iterations() * static_cast<std::int64_t>(j.size()));
-}
-BENCHMARK_CAPTURE(GetVectorInt, signed_ints, TEST_DATA_DIRECTORY "/regression/signed_ints.json");
-
-static void GetVectorDouble(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename);
-
-    for (auto _ : state)
-    {
-        auto v = j.get<std::vector<double>>();
-        benchmark::DoNotOptimize(v);
-    }
-
-    state.SetItemsProcessed(state.iterations() * static_cast<std::int64_t>(j.size()));
-}
-BENCHMARK_CAPTURE(GetVectorDouble, floats, TEST_DATA_DIRECTORY "/regression/floats.json");
-
-// a large flat object: the flattened document, one member per scalar
-static void GetMap(benchmark::State& state, const char* filename)
-{
-    const json j = load_json(filename).flatten();
-
-    for (auto _ : state)
-    {
-        auto m = j.get<std::map<std::string, json>>();
-        benchmark::DoNotOptimize(m);
-    }
-
-    state.SetItemsProcessed(state.iterations() * static_cast<std::int64_t>(j.size()));
-}
-BENCHMARK_CAPTURE(GetMap, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
-
-/// 100,000 strings, each too long for the small string optimization
-static std::vector<std::string> make_strings()
-{
-    std::vector<std::string> result;
-    result.reserve(100000);
-    for (std::size_t i = 0; i < 100000; ++i)
-    {
-        result.push_back("a string that does not fit in place: " + std::to_string(i));
-    }
-    return result;
-}
-
-static void ToJsonStrings(benchmark::State& state, const bool move)
-{
-    const std::vector<std::string> strings = make_strings();
-
-    for (auto _ : state)
-    {
-        state.PauseTiming();
-        std::vector<std::string> input = strings;
-        state.ResumeTiming();
-
-        // destroyed inside the timed section, like the copies above
-        auto* j = move ? new json(std::move(input)) : new json(input);
-        delete j;
-    }
-
-    state.SetItemsProcessed(state.iterations() * static_cast<std::int64_t>(strings.size()));
-}
-BENCHMARK_CAPTURE(ToJsonStrings, copy, false);
-BENCHMARK_CAPTURE(ToJsonStrings, move, true);
-
 // conversion of a JSON array into standard containers
 template<typename Container>
 static void GetArray(benchmark::State& state)

tests/src/unit-qt_keywords.cpp

@@ -0,0 +1,67 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.12.0
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
+#include "doctest_compatibility.h"
+
+// Qt defines its keywords as macros (see qtmetamacros.h and qforeach.h) unless
+// QT_NO_KEYWORDS is defined, and it is common to include Qt headers before this
+// library; it must therefore not use these words as identifiers (see #5865)
+#define slots
+#define signals public
+#define emit
+#define Q_FOREACH(variable, container) for (variable : container) // NOLINT(bugprone-macro-parentheses): variable is a declaration, as in Qt
+#define foreach Q_FOREACH
+#define forever for (;;)
+
+#include <nlohmann/json.hpp>
+using nlohmann::json;
+
+TEST_CASE("Qt keyword macros")
+{
+    SECTION("parse and dump")
+    {
+        const json j = json::parse(R"({"a": [1, 2.5, "x", null, true]})");
+        CHECK(j.dump() == R"({"a":[1,2.5,"x",null,true]})");
+    }
+
+    SECTION("flatten and unflatten")
+    {
+        const json j = {{"a", {{"b", {1, 2}}, {"c", "d"}}}, {"e", nullptr}};
+        CHECK(j.flatten().unflatten() == j);
+    }
+
+    SECTION("JSON pointer")
+    {
+        json j = {{"a", {{"b", {1, 2}}}}};
+        CHECK(j.at(json::json_pointer("/a/b/1")) == 2);
+        j[json::json_pointer("/a/c")] = 3;
+        CHECK(j.contains(json::json_pointer("/a/c")));
+    }
+
+    SECTION("binary formats")
+    {
+        const json j = {{"a", {1, 2, 3}}, {"b", "c"}};
+        CHECK(json::from_cbor(json::to_cbor(j)) == j);
+        CHECK(json::from_msgpack(json::to_msgpack(j)) == j);
+        CHECK(json::from_ubjson(json::to_ubjson(j)) == j);
+        CHECK(json::from_bjdata(json::to_bjdata(j)) == j);
+        CHECK(json::from_bson(json::to_bson(j)) == j);
+    }
+
+    SECTION("patch and diff")
+    {
+        const json source = {{"a", 1}, {"b", {1, 2}}};
+        const json target = {{"a", 2}, {"c", "d"}};
+        CHECK(source.patch(json::diff(source, target)) == target);
+    }
+}
+
+// testing for the macros also keeps -Wunused-macros from rejecting them
+#if !defined(slots) || !defined(signals) || !defined(emit) || !defined(Q_FOREACH) || !defined(foreach) || !defined(forever)
+    #error "the Qt keyword macros must stay defined for the tests above"
+#endif