Add C++17 copies of the test binaries

.clang-tidy

@@ -34,9 +34,11 @@ Checks: '*,
          -llvmlibc-*,
          -misc-no-recursion,
          -misc-non-private-member-variables-in-classes,
+         -modernize-concat-nested-namespaces,
+         -modernize-use-nodiscard,
          -modernize-use-trailing-return-type,
-         -readability-function-size,
          -readability-function-cognitive-complexity,
+         -readability-function-size,
          -readability-identifier-length,
          -readability-magic-numbers,
          -readability-redundant-access-specifiers,

.github/workflows/ubuntu.yml

@@ -11,7 +11,7 @@ on:
 jobs:
   ci_test_clang:
     runs-on: ubuntu-latest
-    container: ghcr.io/nlohmann/json-ci:v2.0.0
+    container: ghcr.io/nlohmann/json-ci:v2.1.0
     steps:
       - uses: actions/checkout@v2
       - name: cmake
@@ -21,7 +21,7 @@ jobs:
 
   ci_test_gcc:
     runs-on: ubuntu-latest
-    container: ghcr.io/nlohmann/json-ci:v2.0.0
+    container: ghcr.io/nlohmann/json-ci:v2.1.0
     steps:
       - uses: actions/checkout@v2
       - name: cmake
@@ -31,7 +31,7 @@ jobs:
 
   ci_static_analysis:
     runs-on: ubuntu-latest
-    container: ghcr.io/nlohmann/json-ci:v2.0.0
+    container: ghcr.io/nlohmann/json-ci:v2.1.0
     strategy:
       matrix:
         target: [ci_clang_tidy, ci_cppcheck, ci_test_valgrind, ci_test_clang_sanitizer, ci_test_amalgamation, ci_clang_analyze, ci_cpplint, ci_cmake_flags, ci_single_binaries, ci_reproducible_tests, ci_non_git_tests, ci_offline_testdata, ci_infer]
@@ -44,7 +44,7 @@ jobs:
 
   ci_cmake_options:
     runs-on: ubuntu-latest
-    container: ghcr.io/nlohmann/json-ci:v2.0.0
+    container: ghcr.io/nlohmann/json-ci:v2.1.0
     strategy:
       matrix:
         target: [ci_test_diagnostics, ci_test_noexceptions, ci_test_noimplicitconversions]
@@ -57,7 +57,7 @@ jobs:
 
   ci_test_coverage:
     runs-on: ubuntu-latest
-    container: ghcr.io/nlohmann/json-ci:v2.0.0
+    container: ghcr.io/nlohmann/json-ci:v2.1.0
     steps:
       - uses: actions/checkout@v2
       - name: cmake
@@ -77,7 +77,7 @@ jobs:
 
   ci_test_compilers:
     runs-on: ubuntu-latest
-    container: ghcr.io/nlohmann/json-ci:v2.0.0
+    container: ghcr.io/nlohmann/json-ci:v2.1.0
     strategy:
       matrix:
         compiler: [g++-4.8, g++-4.9, g++-5, g++-6, g++-7, g++-8, g++-9, g++-10, clang++-3.5, clang++-3.6, clang++-3.7, clang++-3.8, clang++-3.9, clang++-4.0, clang++-5.0, clang++-6.0, clang++-7, clang++-8, clang++-9, clang++-10, clang++-11, clang++-12, clang++-13]
@@ -90,7 +90,7 @@ jobs:
 
   ci_test_standards:
     runs-on: ubuntu-latest
-    container: ghcr.io/nlohmann/json-ci:v2.0.0
+    container: ghcr.io/nlohmann/json-ci:v2.1.0
     strategy:
       matrix:
         standard: [11, 14, 17, 20]

cmake/ci.cmake

@@ -814,11 +814,19 @@ add_custom_target(ci_cmake_flags
 foreach(COMPILER g++-4.8 g++-4.9 g++-5 g++-6 g++-7 g++-8 g++-9 g++-10 clang++-3.5 clang++-3.6 clang++-3.7 clang++-3.8 clang++-3.9 clang++-4.0 clang++-5.0 clang++-6.0 clang++-7 clang++-8 clang++-9 clang++-10 clang++-11 clang++-12 clang++-13)
     find_program(COMPILER_TOOL NAMES ${COMPILER})
     if (COMPILER_TOOL)
+        if ("${COMPILER}" STREQUAL "clang++-9")
+            # fix for https://github.com/nlohmann/json/pull/3101#issuecomment-998788786 / https://stackoverflow.com/a/64051725/266378
+            set(ADDITIONAL_FLAGS "-DCMAKE_CXX_FLAGS=--gcc-toolchain=/root/gcc/9")
+        else()
+            unset(ADDITIONAL_FLAGS)
+        endif()
+
         add_custom_target(ci_test_compiler_${COMPILER}
             COMMAND CXX=${COMPILER} ${CMAKE_COMMAND}
                 -DCMAKE_BUILD_TYPE=Debug -GNinja
                 -DJSON_BuildTests=ON -DJSON_FastTests=ON
                 -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_compiler_${COMPILER}
+                ${ADDITIONAL_FLAGS}
             COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_compiler_${COMPILER}
             COMMAND cd ${PROJECT_BINARY_DIR}/build_compiler_${COMPILER} && ${CMAKE_CTEST_COMMAND} --parallel ${N} --exclude-regex "test-unicode" --output-on-failure
             COMMENT "Compile and test with ${COMPILER}"

doc/mkdocs/docs/features/macros.md

@@ -24,6 +24,13 @@ The diagnostics messages can also be controlled with the CMake option `JSON_Diag
 
 The library targets C++11, but also supports some features introduced in later C++ versions (e.g., `std::string_view` support for C++17). For these new features, the library implements some preprocessor checks to determine the C++ standard. By defining any of these symbols, the internal check is overridden and the provided C++ version is unconditionally assumed. This can be helpful for compilers that only implement parts of the standard and would be detected incorrectly.
 
+## `JSON_HAS_FILESYSTEM`, `JSON_HAS_EXPERIMENTAL_FILESYSTEM`
+
+When compiling with C++17, the library provides conversions from and to `std::filesystem::path`. As compiler support
+for filesystem is limited, the library tries to detect whether `<filesystem>`/`std::filesystem` (`JSON_HAS_FILESYSTEM`)
+or `<experimental/filesystem>`/`std::experimental::filesystem` (`JSON_HAS_EXPERIMENTAL_FILESYSTEM`) should be used.
+To override the built-in check, define `JSON_HAS_FILESYSTEM` or `JSON_HAS_EXPERIMENTAL_FILESYSTEM` to `1`.
+
 ## `JSON_NOEXCEPTION`
 
 Exceptions can be switched off by defining the symbol `JSON_NOEXCEPTION`.

include/nlohmann/byte_container_with_subtype.hpp

@@ -112,7 +112,7 @@ class byte_container_with_subtype : public BinaryType
     */
     constexpr subtype_type subtype() const noexcept
     {
-        return m_has_subtype ? m_subtype : subtype_type(-1);
+        return m_has_subtype ? m_subtype : static_cast<subtype_type>(-1);
     }
 
     /*!

include/nlohmann/detail/conversions/from_json.hpp

@@ -19,8 +19,18 @@
 #include <nlohmann/detail/meta/type_traits.hpp>
 #include <nlohmann/detail/value_t.hpp>
 
-#ifdef JSON_HAS_CPP_17
-    #include <filesystem>
+#if JSON_HAS_EXPERIMENTAL_FILESYSTEM
+#include <experimental/filesystem>
+namespace nlohmann::detail
+{
+namespace std_fs = std::experimental::filesystem;
+} // namespace nlohmann::detail
+#elif JSON_HAS_FILESYSTEM
+#include <filesystem>
+namespace nlohmann::detail
+{
+namespace std_fs = std::filesystem;
+} // namespace nlohmann::detail
 #endif
 
 namespace nlohmann
@@ -448,9 +458,9 @@ void from_json(const BasicJsonType& j, std::unordered_map<Key, Value, Hash, KeyE
     }
 }
 
-#ifdef JSON_HAS_CPP_17
+#if JSON_HAS_FILESYSTEM || JSON_HAS_EXPERIMENTAL_FILESYSTEM
 template<typename BasicJsonType>
-void from_json(const BasicJsonType& j, std::filesystem::path& p)
+void from_json(const BasicJsonType& j, std_fs::path& p)
 {
     if (JSON_HEDLEY_UNLIKELY(!j.is_string()))
     {

include/nlohmann/detail/conversions/to_json.hpp

@@ -15,8 +15,18 @@
 #include <nlohmann/detail/meta/type_traits.hpp>
 #include <nlohmann/detail/value_t.hpp>
 
-#ifdef JSON_HAS_CPP_17
-    #include <filesystem>
+#if JSON_HAS_EXPERIMENTAL_FILESYSTEM
+#include <experimental/filesystem>
+namespace nlohmann::detail
+{
+namespace std_fs = std::experimental::filesystem;
+} // namespace nlohmann::detail
+#elif JSON_HAS_FILESYSTEM
+#include <filesystem>
+namespace nlohmann::detail
+{
+namespace std_fs = std::filesystem;
+} // namespace nlohmann::detail
 #endif
 
 namespace nlohmann
@@ -391,9 +401,9 @@ void to_json(BasicJsonType& j, const T& t)
     to_json_tuple_impl(j, t, make_index_sequence<std::tuple_size<T>::value> {});
 }
 
-#ifdef JSON_HAS_CPP_17
+#if JSON_HAS_FILESYSTEM || JSON_HAS_EXPERIMENTAL_FILESYSTEM
 template<typename BasicJsonType>
-void to_json(BasicJsonType& j, const std::filesystem::path& p)
+void to_json(BasicJsonType& j, const std_fs::path& p)
 {
     j = p.string();
 }

include/nlohmann/detail/input/binary_reader.hpp

@@ -161,7 +161,7 @@ class binary_reader
         std::int32_t document_size{};
         get_number<std::int32_t, true>(input_format_t::bson, document_size);
 
-        if (JSON_HEDLEY_UNLIKELY(!sax->start_object(std::size_t(-1))))
+        if (JSON_HEDLEY_UNLIKELY(!sax->start_object(static_cast<std::size_t>(-1))))
         {
             return false;
         }
@@ -318,7 +318,7 @@ class binary_reader
             default: // anything else not supported (yet)
             {
                 std::array<char, 3> cr{{}};
-                (std::snprintf)(cr.data(), cr.size(), "%.2hhX", static_cast<unsigned char>(element_type)); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
+                static_cast<void>((std::snprintf)(cr.data(), cr.size(), "%.2hhX", static_cast<unsigned char>(element_type))); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
                 return sax->parse_error(element_type_parse_position, std::string(cr.data()), parse_error::create(114, element_type_parse_position, "Unsupported BSON record type 0x" + std::string(cr.data()), BasicJsonType()));
             }
         }
@@ -379,7 +379,7 @@ class binary_reader
         std::int32_t document_size{};
         get_number<std::int32_t, true>(input_format_t::bson, document_size);
 
-        if (JSON_HEDLEY_UNLIKELY(!sax->start_array(std::size_t(-1))))
+        if (JSON_HEDLEY_UNLIKELY(!sax->start_array(static_cast<std::size_t>(-1))))
         {
             return false;
         }
@@ -638,7 +638,7 @@ class binary_reader
             }
 
             case 0x9F: // array (indefinite length)
-                return get_cbor_array(std::size_t(-1), tag_handler);
+                return get_cbor_array(static_cast<std::size_t>(-1), tag_handler);
 
             // map (0x00..0x17 pairs of data items follow)
             case 0xA0:
@@ -692,7 +692,7 @@ class binary_reader
             }
 
             case 0xBF: // map (indefinite length)
-                return get_cbor_object(std::size_t(-1), tag_handler);
+                return get_cbor_object(static_cast<std::size_t>(-1), tag_handler);
 
             case 0xC6: // tagged item
             case 0xC7:
@@ -1076,7 +1076,7 @@ class binary_reader
     }
 
     /*!
-    @param[in] len  the length of the array or std::size_t(-1) for an
+    @param[in] len  the length of the array or static_cast<std::size_t>(-1) for an
                     array of indefinite size
     @param[in] tag_handler how CBOR tags should be treated
     @return whether array creation completed
@@ -1089,7 +1089,7 @@ class binary_reader
             return false;
         }
 
-        if (len != std::size_t(-1))
+        if (len != static_cast<std::size_t>(-1))
         {
             for (std::size_t i = 0; i < len; ++i)
             {
@@ -1114,7 +1114,7 @@ class binary_reader
     }
 
     /*!
-    @param[in] len  the length of the object or std::size_t(-1) for an
+    @param[in] len  the length of the object or static_cast<std::size_t>(-1) for an
                     object of indefinite size
     @param[in] tag_handler how CBOR tags should be treated
     @return whether object creation completed
@@ -1130,7 +1130,7 @@ class binary_reader
         if (len != 0)
         {
             string_t key;
-            if (len != std::size_t(-1))
+            if (len != static_cast<std::size_t>(-1))
             {
                 for (std::size_t i = 0; i < len; ++i)
                 {
@@ -2140,7 +2140,7 @@ class binary_reader
         }
         else
         {
-            if (JSON_HEDLEY_UNLIKELY(!sax->start_array(std::size_t(-1))))
+            if (JSON_HEDLEY_UNLIKELY(!sax->start_array(static_cast<std::size_t>(-1))))
             {
                 return false;
             }
@@ -2210,7 +2210,7 @@ class binary_reader
         }
         else
         {
-            if (JSON_HEDLEY_UNLIKELY(!sax->start_object(std::size_t(-1))))
+            if (JSON_HEDLEY_UNLIKELY(!sax->start_object(static_cast<std::size_t>(-1))))
             {
                 return false;
             }
@@ -2462,7 +2462,7 @@ class binary_reader
     std::string get_token_string() const
     {
         std::array<char, 3> cr{{}};
-        (std::snprintf)(cr.data(), cr.size(), "%.2hhX", static_cast<unsigned char>(current)); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
+        static_cast<void>((std::snprintf)(cr.data(), cr.size(), "%.2hhX", static_cast<unsigned char>(current))); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
         return std::string{cr.data()};
     }
 

include/nlohmann/detail/input/json_sax.hpp

@@ -222,7 +222,7 @@ class json_sax_dom_parser
     {
         ref_stack.push_back(handle_value(BasicJsonType::value_t::object));
 
-        if (JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) && len > ref_stack.back()->max_size()))
+        if (JSON_HEDLEY_UNLIKELY(len != static_cast<std::size_t>(-1) && len > ref_stack.back()->max_size()))
         {
             JSON_THROW(out_of_range::create(408, "excessive object size: " + std::to_string(len), *ref_stack.back()));
         }
@@ -248,7 +248,7 @@ class json_sax_dom_parser
     {
         ref_stack.push_back(handle_value(BasicJsonType::value_t::array));
 
-        if (JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) && len > ref_stack.back()->max_size()))
+        if (JSON_HEDLEY_UNLIKELY(len != static_cast<std::size_t>(-1) && len > ref_stack.back()->max_size()))
         {
             JSON_THROW(out_of_range::create(408, "excessive array size: " + std::to_string(len), *ref_stack.back()));
         }
@@ -403,7 +403,7 @@ class json_sax_dom_callback_parser
         ref_stack.push_back(val.second);
 
         // check object limit
-        if (ref_stack.back() && JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) && len > ref_stack.back()->max_size()))
+        if (ref_stack.back() && JSON_HEDLEY_UNLIKELY(len != static_cast<std::size_t>(-1) && len > ref_stack.back()->max_size()))
         {
             JSON_THROW(out_of_range::create(408, "excessive object size: " + std::to_string(len), *ref_stack.back()));
         }
@@ -473,7 +473,7 @@ class json_sax_dom_callback_parser
         ref_stack.push_back(val.second);
 
         // check array limit
-        if (ref_stack.back() && JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) && len > ref_stack.back()->max_size()))
+        if (ref_stack.back() && JSON_HEDLEY_UNLIKELY(len != static_cast<std::size_t>(-1) && len > ref_stack.back()->max_size()))
         {
             JSON_THROW(out_of_range::create(408, "excessive array size: " + std::to_string(len), *ref_stack.back()));
         }
@@ -676,7 +676,7 @@ class json_sax_acceptor
         return true;
     }
 
-    bool start_object(std::size_t /*unused*/ = std::size_t(-1))
+    bool start_object(std::size_t /*unused*/ = static_cast<std::size_t>(-1))
     {
         return true;
     }
@@ -691,7 +691,7 @@ class json_sax_acceptor
         return true;
     }
 
-    bool start_array(std::size_t /*unused*/ = std::size_t(-1))
+    bool start_array(std::size_t /*unused*/ = static_cast<std::size_t>(-1))
     {
         return true;
     }

include/nlohmann/detail/input/lexer.hpp

@@ -1447,7 +1447,7 @@ class lexer : public lexer_base<BasicJsonType>
             {
                 // escape control characters
                 std::array<char, 9> cs{{}};
-                (std::snprintf)(cs.data(), cs.size(), "<U+%.4X>", static_cast<unsigned char>(c)); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
+                static_cast<void>((std::snprintf)(cs.data(), cs.size(), "<U+%.4X>", static_cast<unsigned char>(c))); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
                 result += cs.data();
             }
             else
@@ -1541,17 +1541,17 @@ class lexer : public lexer_base<BasicJsonType>
             // literals
             case 't':
             {
-                std::array<char_type, 4> true_literal = {{char_type('t'), char_type('r'), char_type('u'), char_type('e')}};
+                std::array<char_type, 4> true_literal = {{static_cast<char_type>('t'), static_cast<char_type>('r'), static_cast<char_type>('u'), static_cast<char_type>('e')}};
                 return scan_literal(true_literal.data(), true_literal.size(), token_type::literal_true);
             }
             case 'f':
             {
-                std::array<char_type, 5> false_literal = {{char_type('f'), char_type('a'), char_type('l'), char_type('s'), char_type('e')}};
+                std::array<char_type, 5> false_literal = {{static_cast<char_type>('f'), static_cast<char_type>('a'), static_cast<char_type>('l'), static_cast<char_type>('s'), static_cast<char_type>('e')}};
                 return scan_literal(false_literal.data(), false_literal.size(), token_type::literal_false);
             }
             case 'n':
             {
-                std::array<char_type, 4> null_literal = {{char_type('n'), char_type('u'), char_type('l'), char_type('l')}};
+                std::array<char_type, 4> null_literal = {{static_cast<char_type>('n'), static_cast<char_type>('u'), static_cast<char_type>('l'), static_cast<char_type>('l')}};
                 return scan_literal(null_literal.data(), null_literal.size(), token_type::literal_null);
             }
 

include/nlohmann/detail/input/parser.hpp

@@ -186,7 +186,7 @@ class parser
                 {
                     case token_type::begin_object:
                     {
-                        if (JSON_HEDLEY_UNLIKELY(!sax->start_object(std::size_t(-1))))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->start_object(static_cast<std::size_t>(-1))))
                         {
                             return false;
                         }
@@ -231,7 +231,7 @@ class parser
 
                     case token_type::begin_array:
                     {
-                        if (JSON_HEDLEY_UNLIKELY(!sax->start_array(std::size_t(-1))))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->start_array(static_cast<std::size_t>(-1))))
                         {
                             return false;
                         }