json/include/nlohmann/detail/iterators/iterator_traits.hpp
Florian Albrechtskirchinger d909f80960
Add versioned, ABI-tagged inline namespace and namespace macros (#3590)
* Add versioned inline namespace

Add a versioned inline namespace to prevent ABI issues when linking code
using multiple library versions.

* Add namespace macros

* Encode ABI information in inline namespace

Add _diag suffix to inline namespace if JSON_DIAGNOSTICS is enabled, and
_ldvcmp suffix if JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON is enabled.

* Move ABI-affecting macros into abi_macros.hpp

* Move std_fs namespace definition into std_fs.hpp

* Remove std_fs namespace from unit test

* Format more files in tests directory

* Add unit tests

* Update documentation

* Fix GDB pretty printer

* fixup! Add namespace macros

* Derive ABI prefix from NLOHMANN_JSON_VERSION_*
2022-07-30 21:59:13 +02:00

62 lines
1.7 KiB
C++

// __ _____ _____ _____
// __| | __| | | | JSON for Modern C++
// | | |__ | | | | | | version 3.10.5
// |_____|_____|_____|_|___| 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