json_custom_base_class.h

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//     __ _____ _____ _____
//  __|  |   __|     |   | |  JSON for Modern C++
// |  |  |__   |  |  | | | |  version 3.11.3
// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
//
// SPDX-FileCopyrightText: 2013-2023 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT
 
#pragma once
 
#include <type_traits> // conditional, is_same
 
#include <wpi/detail/abi_macros.h>
 
WPI_JSON_NAMESPACE_BEGIN
namespace detail
{
 
/*!
@brief Default base class of the @ref basic_json class.
 
So that the correct implementations of the copy / move ctors / assign operators
of @ref basic_json do not require complex case distinctions
(no base class / custom base class used as customization point),
@ref basic_json always has a base class.
By default, this class is used because it is empty and thus has no effect
on the behavior of @ref basic_json.
*/
struct json_default_base {};
 
template<class T>
using json_base_class = typename std::conditional <
                        std::is_same<T, void>::value,
                        json_default_base,
                        T
                        >::type;
 
}  // namespace detail
WPI_JSON_NAMESPACE_END