json/develop/detail/macro_scope.hpp

#pragma once

// This file contains all internal macro definitions
// You MUST include macro_unscope.hpp at the end of json.hpp to undef all of them

// exclude unsupported compilers
#if defined(__clang__)
    #if (__clang_major__ * 10000 + __clang_minor__ * 100 + __clang_patchlevel__) < 30400
        #error "unsupported Clang version - see https://github.com/nlohmann/json#supported-compilers"
    #endif
#elif defined(__GNUC__) && !(defined(__ICC) || defined(__INTEL_COMPILER))
    #if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) < 40900
        #error "unsupported GCC version - see https://github.com/nlohmann/json#supported-compilers"
    #endif
#endif

// disable float-equal warnings on GCC/clang
#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
    #pragma GCC diagnostic push
    #pragma GCC diagnostic ignored "-Wfloat-equal"
#endif

// disable documentation warnings on clang
#if defined(__clang__)
    #pragma GCC diagnostic push
    #pragma GCC diagnostic ignored "-Wdocumentation"
#endif

// allow for portable deprecation warnings
#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
    #define JSON_DEPRECATED __attribute__((deprecated))
#elif defined(_MSC_VER)
    #define JSON_DEPRECATED __declspec(deprecated)
#else
    #define JSON_DEPRECATED
#endif

// allow to disable exceptions
#if (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)) && !defined(JSON_NOEXCEPTION)
    #define JSON_THROW(exception) throw exception
    #define JSON_TRY try
    #define JSON_CATCH(exception) catch(exception)
#else
    #define JSON_THROW(exception) std::abort()
    #define JSON_TRY if(true)
    #define JSON_CATCH(exception) if(false)
#endif

// manual branch prediction
#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
    #define JSON_LIKELY(x)      __builtin_expect(!!(x), 1)
    #define JSON_UNLIKELY(x)    __builtin_expect(!!(x), 0)
#else
    #define JSON_LIKELY(x)      x
    #define JSON_UNLIKELY(x)    x
#endif

// C++ language standard detection
#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464
    #define JSON_HAS_CPP_17
    #define JSON_HAS_CPP_14
#elif (defined(__cplusplus) && __cplusplus >= 201402L) || (defined(_HAS_CXX14) && _HAS_CXX14 == 1)
    #define JSON_HAS_CPP_14
#endif

// Ugly macros to avoid uglier copy-paste when specializing basic_json. They
// may be removed in the future once the class is split.

#define NLOHMANN_BASIC_JSON_TPL_DECLARATION                                \
    template<template<typename, typename, typename...> class ObjectType,   \
             template<typename, typename...> class ArrayType,              \
             class StringType, class BooleanType, class NumberIntegerType, \
             class NumberUnsignedType, class NumberFloatType,              \
             template<typename> class AllocatorType,                       \
             template<typename, typename = void> class JSONSerializer>

#define NLOHMANN_BASIC_JSON_TPL                                            \
    basic_json<ObjectType, ArrayType, StringType, BooleanType,             \
    NumberIntegerType, NumberUnsignedType, NumberFloatType,                \
    AllocatorType, JSONSerializer>

/*!
@brief Helper to determine whether there's a key_type for T.

This helper is used to tell associative containers apart from other containers
such as sequence containers. For instance, `std::map` passes the test as it
contains a `mapped_type`, whereas `std::vector` fails the test.

@sa http://stackoverflow.com/a/7728728/266378
@since version 1.0.0, overworked in version 2.0.6
*/
#define NLOHMANN_JSON_HAS_HELPER(type)                                        \
    template<typename T> struct has_##type {                                  \
    private:                                                                  \
        template<typename U, typename = typename U::type>                     \
        static int detect(U &&);                                              \
        static void detect(...);                                              \
    public:                                                                   \
        static constexpr bool value =                                         \
                std::is_integral<decltype(detect(std::declval<T>()))>::value; \
    }