d2tweaks-rnd2k/vcpkg/nlohmann-json_x86-windows-static/include/nlohmann/detail/json_ref.hpp
2024-04-16 21:45:38 -06:00

77 lines
1.7 KiB
C++

#pragma once
#include <initializer_list>
#include <utility>
#include <nlohmann/detail/meta/type_traits.hpp>
namespace nlohmann
{
namespace detail
{
template<typename BasicJsonType>
class json_ref
{
public:
using value_type = BasicJsonType;
json_ref(value_type&& value)
: owned_value(std::move(value))
, value_ref(&owned_value)
, is_rvalue(true)
{}
json_ref(const value_type& value)
: value_ref(const_cast<value_type*>(&value))
, is_rvalue(false)
{}
json_ref(std::initializer_list<json_ref> init)
: owned_value(init)
, value_ref(&owned_value)
, is_rvalue(true)
{}
template <
class... Args,
enable_if_t<std::is_constructible<value_type, Args...>::value, int> = 0 >
json_ref(Args && ... args)
: owned_value(std::forward<Args>(args)...)
, value_ref(&owned_value)
, is_rvalue(true)
{}
// class should be movable only
json_ref(json_ref&&) = default;
json_ref(const json_ref&) = delete;
json_ref& operator=(const json_ref&) = delete;
json_ref& operator=(json_ref&&) = delete;
~json_ref() = default;
value_type moved_or_copied() const
{
if (is_rvalue)
{
return std::move(*value_ref);
}
return *value_ref;
}
value_type const& operator*() const
{
return *static_cast<value_type const*>(value_ref);
}
value_type const* operator->() const
{
return static_cast<value_type const*>(value_ref);
}
private:
mutable value_type owned_value = nullptr;
value_type* value_ref = nullptr;
const bool is_rvalue = true;
};
} // namespace detail
} // namespace nlohmann