meta()

template<template< typename U, typename V, typename... Args > class ObjectType = std::map, template< typename U, typename... Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::meta ( )

inlinestatic

returns version information on the library

This function returns a JSON object with information about the library, including the version number and information on the platform and compiler.

Returns

JSON object holding version information

key	description
compiler	Information on the used compiler. It is an object with the following keys: c++ (the used C++ standard), family (the compiler family; possible values are clang, icc, gcc, ilecpp, msvc, pgcpp, sunpro, and unknown), and version (the compiler version).
copyright	The copyright line for the library as string.
name	The name of the library as string.
platform	The used platform as string. Possible values are win32, linux, apple, unix, and unknown.
url	The URL of the project as string.
version	The version of the library. It is an object with the following keys: major, minor, and patch as defined by Semantic Versioning, and string (the version string).

@liveexample{The following code shows an example output of the meta() function.,meta}

@exceptionsafety Strong guarantee: if an exception is thrown, there are no changes to any JSON value.

@complexity Constant.

Since

2.1.0

Definition at line 18037 of file json.hpp.

    {
        basic_json result;
        result["copyright"] = "(C) 2013-2021 Niels Lohmann";
        result["name"] = "JSON for Modern C++";
        result["url"] = "https://github.com/nlohmann/json";
        result["version"]["string"] =
            std::to_string(NLOHMANN_JSON_VERSION_MAJOR) + "." +
            std::to_string(NLOHMANN_JSON_VERSION_MINOR) + "." +
            std::to_string(NLOHMANN_JSON_VERSION_PATCH);
        result["version"]["major"] = NLOHMANN_JSON_VERSION_MAJOR;
        result["version"]["minor"] = NLOHMANN_JSON_VERSION_MINOR;
        result["version"]["patch"] = NLOHMANN_JSON_VERSION_PATCH;
#ifdef _WIN32
        result["platform"] = "win32";
#elif defined __linux__
        result["platform"] = "linux";
#elif defined __APPLE__
        result["platform"] = "apple";
#elif defined __unix__
        result["platform"] = "unix";
#else
        result["platform"] = "unknown";
#endif
#if defined(__ICC) || defined(__INTEL_COMPILER)
        result["compiler"] = {{"family", "icc"}, {"version", __INTEL_COMPILER}};
#elif defined(__clang__)
        result["compiler"] = {{"family", "clang"}, {"version", __clang_version__}};
#elif defined(__GNUC__) || defined(__GNUG__)
        result["compiler"] = {{"family", "gcc"}, {"version", std::to_string(__GNUC__) + "." + std::to_string(__GNUC_MINOR__) + "." + std::to_string(__GNUC_PATCHLEVEL__)}};
#elif defined(__HP_cc) || defined(__HP_aCC)
        result["compiler"] = "hp"
#elif defined(__IBMCPP__)
        result["compiler"] = {{"family", "ilecpp"}, {"version", __IBMCPP__}};
#elif defined(_MSC_VER)
        result["compiler"] = {{"family", "msvc"}, {"version", _MSC_VER}};
#elif defined(__PGI)
        result["compiler"] = {{"family", "pgcpp"}, {"version", __PGI}};
#elif defined(__SUNPRO_CC)
        result["compiler"] = {{"family", "sunpro"}, {"version", __SUNPRO_CC}};
#else
        result["compiler"] = {{"family", "unknown"}, {"version", "unknown"}};
#endif
#ifdef __cplusplus
        result["compiler"]["c++"] = std::to_string(__cplusplus);
#else
        result["compiler"]["c++"] = "unknown";
#endif
        return result;
    }