json/include/nlohmann/detail/iterators/iterator_traits.hpp
2022-08-12 15:04:06 +02:00

62 lines
1.7 KiB
C++

// __ _____ _____ _____
// __| | __| | | | JSON for Modern C++
// | | |__ | | | | | | version 3.11.2
// |_____|_____|_____|_|___| https://github.com/nlohmann/json
//
// SPDX-FileCopyrightText: 2013-2022 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT
#pragma once
#include <iterator> // random_access_iterator_tag
#include <nlohmann/detail/abi_macros.hpp>
#include <nlohmann/detail/meta/void_t.hpp>
#include <nlohmann/detail/meta/cpp_future.hpp>
NLOHMANN_JSON_NAMESPACE_BEGIN
namespace detail
{
template<typename It, typename = void>
struct iterator_types {};
template<typename It>
struct iterator_types <
It,
void_t<typename It::difference_type, typename It::value_type, typename It::pointer,
typename It::reference, typename It::iterator_category >>
{
using difference_type = typename It::difference_type;
using value_type = typename It::value_type;
using pointer = typename It::pointer;
using reference = typename It::reference;
using iterator_category = typename It::iterator_category;
};
// This is required as some compilers implement std::iterator_traits in a way that
// doesn't work with SFINAE. See https://github.com/nlohmann/json/issues/1341.
template<typename T, typename = void>
struct iterator_traits
{
};
template<typename T>
struct iterator_traits < T, enable_if_t < !std::is_pointer<T>::value >>
: iterator_types<T>
{
};
template<typename T>
struct iterator_traits<T*, enable_if_t<std::is_object<T>::value>>
{
using iterator_category = std::random_access_iterator_tag;
using value_type = T;
using difference_type = ptrdiff_t;
using pointer = T*;
using reference = T&;
};
} // namespace detail
NLOHMANN_JSON_NAMESPACE_END