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