2357 lines
77 KiB
Plaintext
2357 lines
77 KiB
Plaintext
// Copyright 2017 Dolphin Emulator Project
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// Licensed under GPLv2+
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// Refer to the license.txt file included.
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#pragma once
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#if __has_include_next(<variant>)
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#include_next <variant>
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#else
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// MPark.Variant
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//
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// Copyright Michael Park, 2015-2017
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//
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
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/*
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variant synopsis
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namespace std {
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// 20.7.2, class template variant
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template <class... Types>
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class variant {
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public:
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// 20.7.2.1, constructors
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constexpr variant() noexcept(see below);
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variant(const variant&);
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variant(variant&&) noexcept(see below);
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template <class T> constexpr variant(T&&) noexcept(see below);
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template <class T, class... Args>
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constexpr explicit variant(::std::in_place_type_t<T>, Args&&...);
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template <class T, class U, class... Args>
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constexpr explicit variant(
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::std::in_place_type_t<T>, initializer_list<U>, Args&&...);
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template <size_t I, class... Args>
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constexpr explicit variant(::std::in_place_index_t<I>, Args&&...);
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template <size_t I, class U, class... Args>
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constexpr explicit variant(
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::std::in_place_index_t<I>, initializer_list<U>, Args&&...);
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// 20.7.2.2, destructor
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~variant();
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// 20.7.2.3, assignment
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variant& operator=(const variant&);
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variant& operator=(variant&&) noexcept(see below);
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template <class T> variant& operator=(T&&) noexcept(see below);
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// 20.7.2.4, modifiers
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template <class T, class... Args>
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T& emplace(Args&&...);
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template <class T, class U, class... Args>
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T& emplace(initializer_list<U>, Args&&...);
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template <size_t I, class... Args>
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variant_alternative<I, variant>& emplace(Args&&...);
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template <size_t I, class U, class... Args>
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variant_alternative<I, variant>& emplace(initializer_list<U>, Args&&...);
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// 20.7.2.5, value status
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constexpr bool valueless_by_exception() const noexcept;
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constexpr size_t index() const noexcept;
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// 20.7.2.6, swap
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void swap(variant&) noexcept(see below);
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};
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// 20.7.3, variant helper classes
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template <class T> struct variant_size; // undefined
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template <class T>
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constexpr size_t variant_size_v = variant_size<T>::value;
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template <class T> struct variant_size<const T>;
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template <class T> struct variant_size<volatile T>;
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template <class T> struct variant_size<const volatile T>;
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template <class... Types>
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struct variant_size<variant<Types...>>;
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template <size_t I, class T> struct variant_alternative; // undefined
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template <size_t I, class T>
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using variant_alternative_t = typename variant_alternative<I, T>::type;
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template <size_t I, class T> struct variant_alternative<I, const T>;
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template <size_t I, class T> struct variant_alternative<I, volatile T>;
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template <size_t I, class T> struct variant_alternative<I, const volatile T>;
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template <size_t I, class... Types>
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struct variant_alternative<I, variant<Types...>>;
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constexpr size_t variant_npos = -1;
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// 20.7.4, value access
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template <class T, class... Types>
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constexpr bool holds_alternative(const variant<Types...>&) noexcept;
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template <size_t I, class... Types>
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constexpr variant_alternative_t<I, variant<Types...>>&
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get(variant<Types...>&);
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template <size_t I, class... Types>
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constexpr variant_alternative_t<I, variant<Types...>>&&
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get(variant<Types...>&&);
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template <size_t I, class... Types>
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constexpr variant_alternative_t<I, variant<Types...>> const&
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get(const variant<Types...>&);
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template <size_t I, class... Types>
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constexpr variant_alternative_t<I, variant<Types...>> const&&
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get(const variant<Types...>&&);
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template <class T, class... Types>
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constexpr T& get(variant<Types...>&);
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template <class T, class... Types>
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constexpr T&& get(variant<Types...>&&);
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template <class T, class... Types>
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constexpr const T& get(const variant<Types...>&);
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template <class T, class... Types>
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constexpr const T&& get(const variant<Types...>&&);
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template <size_t I, class... Types>
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constexpr add_pointer_t<variant_alternative_t<I, variant<Types...>>>
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get_if(variant<Types...>*) noexcept;
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template <size_t I, class... Types>
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constexpr add_pointer_t<const variant_alternative_t<I, variant<Types...>>>
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get_if(const variant<Types...>*) noexcept;
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template <class T, class... Types>
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constexpr add_pointer_t<T>
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get_if(variant<Types...>*) noexcept;
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template <class T, class... Types>
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constexpr add_pointer_t<const T>
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get_if(const variant<Types...>*) noexcept;
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// 20.7.5, relational operators
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template <class... Types>
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constexpr bool operator==(const variant<Types...>&, const variant<Types...>&);
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template <class... Types>
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constexpr bool operator!=(const variant<Types...>&, const variant<Types...>&);
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template <class... Types>
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constexpr bool operator<(const variant<Types...>&, const variant<Types...>&);
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template <class... Types>
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constexpr bool operator>(const variant<Types...>&, const variant<Types...>&);
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template <class... Types>
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constexpr bool operator<=(const variant<Types...>&, const variant<Types...>&);
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template <class... Types>
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constexpr bool operator>=(const variant<Types...>&, const variant<Types...>&);
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// 20.7.6, visitation
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template <class Visitor, class... Variants>
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constexpr see below visit(Visitor&&, Variants&&...);
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// 20.7.7, class monostate
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struct monostate;
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// 20.7.8, monostate relational operators
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constexpr bool operator<(monostate, monostate) noexcept;
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constexpr bool operator>(monostate, monostate) noexcept;
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constexpr bool operator<=(monostate, monostate) noexcept;
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constexpr bool operator>=(monostate, monostate) noexcept;
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constexpr bool operator==(monostate, monostate) noexcept;
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constexpr bool operator!=(monostate, monostate) noexcept;
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// 20.7.9, specialized algorithms
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template <class... Types>
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void swap(variant<Types...>&, variant<Types...>&) noexcept(see below);
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// 20.7.10, class bad_variant_access
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class bad_variant_access;
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// 20.7.11, hash support
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template <class T> struct hash;
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template <class... Types> struct hash<variant<Types...>>;
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template <> struct hash<monostate>;
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} // namespace std
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*/
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#include <cstddef>
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#include <exception>
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#include <functional>
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#include <initializer_list>
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#include <new>
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#include <type_traits>
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#include <utility>
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#include "in_place.h"
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// MPark.Variant
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//
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// Copyright Michael Park, 2015-2017
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//
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
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#ifndef MPARK_CONFIG_HPP
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#define MPARK_CONFIG_HPP
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// MSVC 2015 Update 3.
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#if __cplusplus < 201103L && (!defined(_MSC_VER) || _MSC_FULL_VER < 190024215)
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#error "MPark.Variant requires C++11 support."
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#endif
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#ifndef __has_builtin
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#define __has_builtin(x) 0
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#endif
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#ifndef __has_feature
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#define __has_feature(x) 0
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#endif
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#if __has_builtin(__builtin_addressof) || __GNUC__ >= 7 || defined(_MSC_VER)
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#define MPARK_BUILTIN_ADDRESSOF
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#endif
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#if __has_builtin(__type_pack_element)
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#define MPARK_TYPE_PACK_ELEMENT
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#endif
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#if defined(__cpp_constexpr) && __cpp_constexpr >= 201304
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#define MPARK_CPP14_CONSTEXPR
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#endif
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#if __has_feature(cxx_exceptions) || defined(__cpp_exceptions)
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#define MPARK_EXCEPTIONS
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#endif
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#if defined(__cpp_generic_lambdas) || defined(_MSC_VER)
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#define MPARK_GENERIC_LAMBDAS
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#endif
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#if defined(__cpp_lib_integer_sequence)
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#define MPARK_INTEGER_SEQUENCE
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#endif
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#if defined(__cpp_return_type_deduction) || defined(_MSC_VER)
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#define MPARK_RETURN_TYPE_DEDUCTION
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#endif
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#if defined(__cpp_lib_transparent_operators) || defined(_MSC_VER)
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#define MPARK_TRANSPARENT_OPERATORS
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#endif
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#if defined(__cpp_variable_templates) || defined(_MSC_VER)
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#define MPARK_VARIABLE_TEMPLATES
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#endif
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#endif // MPARK_CONFIG_HPP
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// MPark.Variant
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//
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// Copyright Michael Park, 2015-2017
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//
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
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#ifndef MPARK_LIB_HPP
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#define MPARK_LIB_HPP
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#include <functional>
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#include <memory>
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#include <type_traits>
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#include <utility>
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#define RETURN(...) \
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noexcept(noexcept(__VA_ARGS__))->decltype(__VA_ARGS__) { return __VA_ARGS__; }
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namespace mpark
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{
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namespace lib
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{
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template <typename T>
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struct identity
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{
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using type = T;
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};
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inline namespace cpp14
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{
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template <typename T, std::size_t N>
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struct array
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{
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constexpr const T& operator[](std::size_t index) const { return data[index]; }
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T data[N == 0 ? 1 : N];
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};
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template <typename T>
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using add_pointer_t = typename std::add_pointer<T>::type;
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template <typename... Ts>
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using common_type_t = typename std::common_type<Ts...>::type;
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template <typename T>
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using decay_t = typename std::decay<T>::type;
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template <bool B, typename T = void>
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using enable_if_t = typename std::enable_if<B, T>::type;
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template <typename T>
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using remove_const_t = typename std::remove_const<T>::type;
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template <typename T>
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using remove_reference_t = typename std::remove_reference<T>::type;
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template <typename T>
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inline constexpr T&& forward(remove_reference_t<T>& t) noexcept
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{
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return static_cast<T&&>(t);
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}
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template <typename T>
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inline constexpr T&& forward(remove_reference_t<T>&& t) noexcept
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{
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static_assert(!std::is_lvalue_reference<T>::value, "can not forward an rvalue as an lvalue");
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return static_cast<T&&>(t);
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}
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template <typename T>
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constexpr remove_reference_t<T>&& move(T&& t) noexcept
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{
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return static_cast<remove_reference_t<T>&&>(t);
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}
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#ifdef MPARK_INTEGER_SEQUENCE
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template <typename T, T... Is>
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using integer_sequence = std::integer_sequence<T, Is...>;
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template <std::size_t... Is>
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using index_sequence = std::index_sequence<Is...>;
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template <std::size_t N>
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using make_index_sequence = std::make_index_sequence<N>;
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template <typename... Ts>
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using index_sequence_for = std::index_sequence_for<Ts...>;
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#else
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template <typename T, T... Is>
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struct integer_sequence
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{
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using value_type = T;
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static constexpr std::size_t size() noexcept { return sizeof...(Is); }
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};
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template <std::size_t... Is>
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using index_sequence = integer_sequence<std::size_t, Is...>;
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template <typename Lhs, typename Rhs>
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struct make_index_sequence_concat;
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template <std::size_t... Lhs, std::size_t... Rhs>
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struct make_index_sequence_concat<index_sequence<Lhs...>, index_sequence<Rhs...>>
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: identity<index_sequence<Lhs..., (sizeof...(Lhs) + Rhs)...>>
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{
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};
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template <std::size_t N>
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struct make_index_sequence_impl;
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template <std::size_t N>
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using make_index_sequence = typename make_index_sequence_impl<N>::type;
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template <std::size_t N>
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struct make_index_sequence_impl
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: make_index_sequence_concat<make_index_sequence<N / 2>, make_index_sequence<N - (N / 2)>>
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{
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};
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template <>
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struct make_index_sequence_impl<0> : identity<index_sequence<>>
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{
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};
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template <>
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struct make_index_sequence_impl<1> : identity<index_sequence<0>>
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{
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};
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template <typename... Ts>
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using index_sequence_for = make_index_sequence<sizeof...(Ts)>;
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#endif
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// <functional>
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#ifdef MPARK_TRANSPARENT_OPERATORS
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using equal_to = std::equal_to<>;
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#else
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struct equal_to
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{
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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs&& lhs, Rhs&& rhs) const
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RETURN(lib::forward<Lhs>(lhs) == lib::forward<Rhs>(rhs))
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};
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#endif
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#ifdef MPARK_TRANSPARENT_OPERATORS
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using not_equal_to = std::not_equal_to<>;
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#else
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struct not_equal_to
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{
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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs&& lhs, Rhs&& rhs) const
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RETURN(lib::forward<Lhs>(lhs) != lib::forward<Rhs>(rhs))
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};
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#endif
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#ifdef MPARK_TRANSPARENT_OPERATORS
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using less = std::less<>;
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#else
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struct less
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{
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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs&& lhs, Rhs&& rhs) const
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RETURN(lib::forward<Lhs>(lhs) < lib::forward<Rhs>(rhs))
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};
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#endif
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#ifdef MPARK_TRANSPARENT_OPERATORS
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using greater = std::greater<>;
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#else
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struct greater
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{
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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs&& lhs, Rhs&& rhs) const
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RETURN(lib::forward<Lhs>(lhs) > lib::forward<Rhs>(rhs))
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};
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#endif
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#ifdef MPARK_TRANSPARENT_OPERATORS
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using less_equal = std::less_equal<>;
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#else
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struct less_equal
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{
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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs&& lhs, Rhs&& rhs) const
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RETURN(lib::forward<Lhs>(lhs) <= lib::forward<Rhs>(rhs))
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};
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#endif
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#ifdef MPARK_TRANSPARENT_OPERATORS
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using greater_equal = std::greater_equal<>;
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#else
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struct greater_equal
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{
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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs&& lhs, Rhs&& rhs) const
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RETURN(lib::forward<Lhs>(lhs) >= lib::forward<Rhs>(rhs))
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};
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#endif
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} // namespace cpp14
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inline namespace cpp17
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{
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// <type_traits>
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template <bool B>
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using bool_constant = std::integral_constant<bool, B>;
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template <typename...>
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using void_t = void;
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namespace detail
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{
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namespace swappable
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{
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using std::swap;
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template <typename T>
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struct is_swappable_impl
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{
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private:
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template <typename U, typename = decltype(swap(std::declval<U&>(), std::declval<U&>()))>
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inline static std::true_type test(int);
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template <typename U>
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inline static std::false_type test(...);
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public:
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using type = decltype(test<T>(0));
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};
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template <typename T>
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using is_swappable = typename is_swappable_impl<T>::type;
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template <typename T, bool = is_swappable<T>::value>
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struct is_nothrow_swappable
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{
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static constexpr bool value = noexcept(swap(std::declval<T&>(), std::declval<T&>()));
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};
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template <typename T>
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struct is_nothrow_swappable<T, false> : std::false_type
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{
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};
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} // namespace swappable
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} // namespace detail
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template <typename T>
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using is_swappable = detail::swappable::is_swappable<T>;
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template <typename T>
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using is_nothrow_swappable = detail::swappable::is_nothrow_swappable<T>;
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// <functional>
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#ifdef _MSC_VER
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#pragma warning(push)
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#pragma warning(disable : 4100)
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#endif
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template <typename F, typename... As>
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inline constexpr auto invoke(F&& f, As&&... as) RETURN(lib::forward<F>(f)(lib::forward<As>(as)...))
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#ifdef _MSC_VER
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#pragma warning(pop)
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#endif
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template <typename B, typename T, typename D>
|
|
inline constexpr auto invoke(T B::*pmv, D&& d) RETURN(lib::forward<D>(d).*pmv)
|
|
|
|
template <typename Pmv, typename Ptr>
|
|
inline constexpr auto invoke(Pmv pmv, Ptr&& ptr) RETURN((*lib::forward<Ptr>(ptr)).*pmv)
|
|
|
|
template <typename B, typename T, typename D, typename... As>
|
|
inline constexpr auto invoke(T B::*pmf, D&& d, As&&... as)
|
|
RETURN((lib::forward<D>(d).*pmf)(lib::forward<As>(as)...))
|
|
|
|
template <typename Pmf, typename Ptr, typename... As>
|
|
inline constexpr auto invoke(Pmf pmf, Ptr&& ptr, As&&... as)
|
|
RETURN(((*lib::forward<Ptr>(ptr)).*pmf)(lib::forward<As>(as)...))
|
|
|
|
namespace detail
|
|
{
|
|
template <typename Void, typename, typename...>
|
|
struct invoke_result
|
|
{
|
|
};
|
|
|
|
template <typename F, typename... Args>
|
|
struct invoke_result<void_t<decltype(lib::invoke(std::declval<F>(), std::declval<Args>()...))>, F,
|
|
Args...>
|
|
: identity<decltype(lib::invoke(std::declval<F>(), std::declval<Args>()...))>
|
|
{
|
|
};
|
|
|
|
} // namespace detail
|
|
|
|
template <typename F, typename... Args>
|
|
using invoke_result = detail::invoke_result<void, F, Args...>;
|
|
|
|
template <typename F, typename... Args>
|
|
using invoke_result_t = typename invoke_result<F, Args...>::type;
|
|
|
|
namespace detail
|
|
{
|
|
template <typename Void, typename, typename...>
|
|
struct is_invocable : std::false_type
|
|
{
|
|
};
|
|
|
|
template <typename F, typename... Args>
|
|
struct is_invocable<void_t<invoke_result_t<F, Args...>>, F, Args...> : std::true_type
|
|
{
|
|
};
|
|
|
|
template <typename Void, typename, typename, typename...>
|
|
struct is_invocable_r : std::false_type
|
|
{
|
|
};
|
|
|
|
template <typename R, typename F, typename... Args>
|
|
struct is_invocable_r<void_t<invoke_result_t<F, Args...>>, R, F, Args...>
|
|
: std::is_convertible<invoke_result_t<F, Args...>, R>
|
|
{
|
|
};
|
|
|
|
} // namespace detail
|
|
|
|
template <typename F, typename... Args>
|
|
using is_invocable = detail::is_invocable<void, F, Args...>;
|
|
|
|
template <typename R, typename F, typename... Args>
|
|
using is_invocable_r = detail::is_invocable_r<void, R, F, Args...>;
|
|
|
|
// <memory>
|
|
#ifdef MPARK_BUILTIN_ADDRESSOF
|
|
template <typename T>
|
|
inline constexpr T* addressof(T& arg)
|
|
{
|
|
return __builtin_addressof(arg);
|
|
}
|
|
#else
|
|
namespace detail
|
|
{
|
|
namespace has_addressof_impl
|
|
{
|
|
struct fail;
|
|
|
|
template <typename T>
|
|
inline fail operator&(T&&);
|
|
|
|
template <typename T>
|
|
inline static constexpr bool impl()
|
|
{
|
|
return (std::is_class<T>::value || std::is_union<T>::value) &&
|
|
!std::is_same<decltype(&std::declval<T&>()), fail>::value;
|
|
}
|
|
|
|
} // namespace has_addressof_impl
|
|
|
|
template <typename T>
|
|
using has_addressof = bool_constant<has_addressof_impl::impl<T>()>;
|
|
|
|
template <typename T>
|
|
inline constexpr T* addressof(T& arg, std::true_type)
|
|
{
|
|
return std::addressof(arg);
|
|
}
|
|
|
|
template <typename T>
|
|
inline constexpr T* addressof(T& arg, std::false_type)
|
|
{
|
|
return &arg;
|
|
}
|
|
|
|
} // namespace detail
|
|
|
|
template <typename T>
|
|
inline constexpr T* addressof(T& arg)
|
|
{
|
|
return detail::addressof(arg, detail::has_addressof<T>{});
|
|
}
|
|
#endif
|
|
|
|
template <typename T>
|
|
inline constexpr T* addressof(const T&&) = delete;
|
|
|
|
} // namespace cpp17
|
|
|
|
template <typename T>
|
|
struct remove_all_extents : identity<T>
|
|
{
|
|
};
|
|
|
|
template <typename T, std::size_t N>
|
|
struct remove_all_extents<array<T, N>> : remove_all_extents<T>
|
|
{
|
|
};
|
|
|
|
template <typename T>
|
|
using remove_all_extents_t = typename remove_all_extents<T>::type;
|
|
|
|
template <std::size_t N>
|
|
using size_constant = std::integral_constant<std::size_t, N>;
|
|
|
|
template <bool... Bs>
|
|
using bool_sequence = integer_sequence<bool, Bs...>;
|
|
|
|
template <std::size_t I, typename T>
|
|
struct indexed_type : size_constant<I>, identity<T>
|
|
{
|
|
};
|
|
|
|
template <bool... Bs>
|
|
using all = std::is_same<bool_sequence<true, Bs...>, bool_sequence<Bs..., true>>;
|
|
|
|
#ifdef MPARK_TYPE_PACK_ELEMENT
|
|
template <std::size_t I, typename... Ts>
|
|
using type_pack_element_t = __type_pack_element<I, Ts...>;
|
|
#else
|
|
template <std::size_t I, typename... Ts>
|
|
struct type_pack_element_impl
|
|
{
|
|
private:
|
|
template <typename>
|
|
struct set;
|
|
|
|
template <std::size_t... Is>
|
|
struct set<index_sequence<Is...>> : indexed_type<Is, Ts>...
|
|
{
|
|
};
|
|
|
|
template <typename T>
|
|
inline static std::enable_if<true, T> impl(indexed_type<I, T>);
|
|
|
|
inline static std::enable_if<false> impl(...);
|
|
|
|
public:
|
|
using type = decltype(impl(set<index_sequence_for<Ts...>>{}));
|
|
};
|
|
|
|
template <std::size_t I, typename... Ts>
|
|
using type_pack_element = typename type_pack_element_impl<I, Ts...>::type;
|
|
|
|
template <std::size_t I, typename... Ts>
|
|
using type_pack_element_t = typename type_pack_element<I, Ts...>::type;
|
|
#endif
|
|
|
|
} // namespace lib
|
|
} // namespace mpark
|
|
|
|
#undef RETURN
|
|
|
|
#endif // MPARK_LIB_HPP
|
|
|
|
namespace mpark
|
|
{
|
|
|
|
#ifdef MPARK_RETURN_TYPE_DEDUCTION
|
|
|
|
#define AUTO auto
|
|
#define AUTO_RETURN(...) \
|
|
{ \
|
|
return __VA_ARGS__; \
|
|
}
|
|
|
|
#define AUTO_REFREF auto&&
|
|
#define AUTO_REFREF_RETURN(...) \
|
|
{ \
|
|
return __VA_ARGS__; \
|
|
}
|
|
|
|
#define DECLTYPE_AUTO decltype(auto)
|
|
#define DECLTYPE_AUTO_RETURN(...) \
|
|
{ \
|
|
return __VA_ARGS__; \
|
|
}
|
|
|
|
#else
|
|
|
|
#define AUTO auto
|
|
#define AUTO_RETURN(...) \
|
|
->lib::decay_t<decltype(__VA_ARGS__)> { return __VA_ARGS__; }
|
|
#define AUTO_REFREF auto
|
|
#define AUTO_REFREF_RETURN(...) \
|
|
->decltype((__VA_ARGS__)) \
|
|
{ \
|
|
static_assert(std::is_reference<decltype((__VA_ARGS__))>::value, ""); \
|
|
return __VA_ARGS__; \
|
|
}
|
|
|
|
#define DECLTYPE_AUTO auto
|
|
#define DECLTYPE_AUTO_RETURN(...) \
|
|
->decltype(__VA_ARGS__) { return __VA_ARGS__; }
|
|
#endif
|
|
|
|
class bad_variant_access : public std::exception
|
|
{
|
|
public:
|
|
virtual const char* what() const noexcept { return "bad_variant_access"; }
|
|
};
|
|
|
|
[[noreturn]] inline void throw_bad_variant_access()
|
|
{
|
|
#ifdef MPARK_EXCEPTIONS
|
|
throw bad_variant_access{};
|
|
#else
|
|
std::terminate();
|
|
#endif
|
|
}
|
|
|
|
template <typename... Ts>
|
|
class variant;
|
|
|
|
template <typename T>
|
|
struct variant_size;
|
|
|
|
#ifdef MPARK_VARIABLE_TEMPLATES
|
|
template <typename T>
|
|
constexpr std::size_t variant_size_v = variant_size<T>::value;
|
|
#endif
|
|
|
|
template <typename T>
|
|
struct variant_size<const T> : variant_size<T>
|
|
{
|
|
};
|
|
|
|
template <typename T>
|
|
struct variant_size<volatile T> : variant_size<T>
|
|
{
|
|
};
|
|
|
|
template <typename T>
|
|
struct variant_size<const volatile T> : variant_size<T>
|
|
{
|
|
};
|
|
|
|
template <typename... Ts>
|
|
struct variant_size<variant<Ts...>> : lib::size_constant<sizeof...(Ts)>
|
|
{
|
|
};
|
|
|
|
template <std::size_t I, typename T>
|
|
struct variant_alternative;
|
|
|
|
template <std::size_t I, typename T>
|
|
using variant_alternative_t = typename variant_alternative<I, T>::type;
|
|
|
|
template <std::size_t I, typename T>
|
|
struct variant_alternative<I, const T> : std::add_const<variant_alternative_t<I, T>>
|
|
{
|
|
};
|
|
|
|
template <std::size_t I, typename T>
|
|
struct variant_alternative<I, volatile T> : std::add_volatile<variant_alternative_t<I, T>>
|
|
{
|
|
};
|
|
|
|
template <std::size_t I, typename T>
|
|
struct variant_alternative<I, const volatile T> : std::add_cv<variant_alternative_t<I, T>>
|
|
{
|
|
};
|
|
|
|
template <std::size_t I, typename... Ts>
|
|
struct variant_alternative<I, variant<Ts...>> : lib::identity<lib::type_pack_element_t<I, Ts...>>
|
|
{
|
|
static_assert(I < sizeof...(Ts), "`variant_alternative` index out of range.");
|
|
};
|
|
|
|
constexpr std::size_t variant_npos = static_cast<std::size_t>(-1);
|
|
|
|
namespace detail
|
|
{
|
|
inline constexpr bool all()
|
|
{
|
|
return true;
|
|
}
|
|
|
|
template <typename... Bs>
|
|
inline constexpr bool all(bool b, Bs... bs)
|
|
{
|
|
return b && all(bs...);
|
|
}
|
|
|
|
constexpr std::size_t not_found = static_cast<std::size_t>(-1);
|
|
constexpr std::size_t ambiguous = static_cast<std::size_t>(-2);
|
|
|
|
#ifdef MPARK_CPP14_CONSTEXPR
|
|
template <typename T, typename... Ts>
|
|
inline constexpr std::size_t find_index()
|
|
{
|
|
constexpr lib::array<bool, sizeof...(Ts)> matches = {{std::is_same<T, Ts>::value...}};
|
|
std::size_t result = not_found;
|
|
for (std::size_t i = 0; i < sizeof...(Ts); ++i)
|
|
{
|
|
if (matches[i])
|
|
{
|
|
if (result != not_found)
|
|
{
|
|
return ambiguous;
|
|
}
|
|
result = i;
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
#else
|
|
inline constexpr std::size_t find_index_impl(std::size_t result, std::size_t)
|
|
{
|
|
return result;
|
|
}
|
|
|
|
template <typename... Bs>
|
|
inline constexpr std::size_t find_index_impl(std::size_t result, std::size_t idx, bool b, Bs... bs)
|
|
{
|
|
return b ? (result != not_found ? ambiguous : find_index_impl(idx, idx + 1, bs...)) :
|
|
find_index_impl(result, idx + 1, bs...);
|
|
}
|
|
|
|
template <typename T, typename... Ts>
|
|
inline constexpr std::size_t find_index()
|
|
{
|
|
return find_index_impl(not_found, 0, std::is_same<T, Ts>::value...);
|
|
}
|
|
#endif
|
|
|
|
template <std::size_t I>
|
|
using find_index_sfinae_impl =
|
|
lib::enable_if_t<I != not_found && I != ambiguous, lib::size_constant<I>>;
|
|
|
|
template <typename T, typename... Ts>
|
|
using find_index_sfinae = find_index_sfinae_impl<find_index<T, Ts...>()>;
|
|
|
|
template <std::size_t I>
|
|
struct find_index_checked_impl : lib::size_constant<I>
|
|
{
|
|
static_assert(I != not_found, "the specified type is not found.");
|
|
static_assert(I != ambiguous, "the specified type is ambiguous.");
|
|
};
|
|
|
|
template <typename T, typename... Ts>
|
|
using find_index_checked = find_index_checked_impl<find_index<T, Ts...>()>;
|
|
|
|
struct valueless_t
|
|
{
|
|
};
|
|
|
|
enum class Trait
|
|
{
|
|
TriviallyAvailable,
|
|
Available,
|
|
Unavailable
|
|
};
|
|
|
|
template <typename T, template <typename> class IsTriviallyAvailable,
|
|
template <typename> class IsAvailable>
|
|
inline constexpr Trait trait()
|
|
{
|
|
return IsTriviallyAvailable<T>::value ? Trait::TriviallyAvailable : IsAvailable<T>::value ?
|
|
Trait::Available :
|
|
Trait::Unavailable;
|
|
}
|
|
|
|
#ifdef MPARK_CPP14_CONSTEXPR
|
|
template <typename... Traits>
|
|
inline constexpr Trait common_trait(Traits... traits)
|
|
{
|
|
Trait result = Trait::TriviallyAvailable;
|
|
for (Trait t : {traits...})
|
|
{
|
|
if (static_cast<int>(t) > static_cast<int>(result))
|
|
{
|
|
result = t;
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
#else
|
|
inline constexpr Trait common_trait_impl(Trait result)
|
|
{
|
|
return result;
|
|
}
|
|
|
|
template <typename... Traits>
|
|
inline constexpr Trait common_trait_impl(Trait result, Trait t, Traits... ts)
|
|
{
|
|
return static_cast<int>(t) > static_cast<int>(result) ? common_trait_impl(t, ts...) :
|
|
common_trait_impl(result, ts...);
|
|
}
|
|
|
|
template <typename... Traits>
|
|
inline constexpr Trait common_trait(Traits... ts)
|
|
{
|
|
return common_trait_impl(Trait::TriviallyAvailable, ts...);
|
|
}
|
|
#endif
|
|
|
|
template <typename... Ts>
|
|
struct traits
|
|
{
|
|
static constexpr Trait copy_constructible_trait = common_trait(
|
|
trait<Ts, std::is_trivially_copy_constructible, std::is_copy_constructible>()...);
|
|
|
|
static constexpr Trait move_constructible_trait = common_trait(
|
|
trait<Ts, std::is_trivially_move_constructible, std::is_move_constructible>()...);
|
|
|
|
static constexpr Trait copy_assignable_trait =
|
|
common_trait(copy_constructible_trait, move_constructible_trait,
|
|
trait<Ts, std::is_trivially_copy_assignable, std::is_copy_assignable>()...);
|
|
|
|
static constexpr Trait move_assignable_trait =
|
|
common_trait(move_constructible_trait,
|
|
trait<Ts, std::is_trivially_move_assignable, std::is_move_assignable>()...);
|
|
|
|
static constexpr Trait destructible_trait =
|
|
common_trait(trait<Ts, std::is_trivially_destructible, std::is_destructible>()...);
|
|
};
|
|
|
|
namespace access
|
|
{
|
|
struct recursive_union
|
|
{
|
|
#ifdef MPARK_RETURN_TYPE_DEDUCTION
|
|
template <typename V>
|
|
inline static constexpr auto&& get_alt(V&& v, ::std::in_place_index_t<0>)
|
|
{
|
|
return lib::forward<V>(v).head_;
|
|
}
|
|
|
|
template <typename V, std::size_t I>
|
|
inline static constexpr auto&& get_alt(V&& v, ::std::in_place_index_t<I>)
|
|
{
|
|
return get_alt(lib::forward<V>(v).tail_, ::std::in_place_index_t<I - 1>{});
|
|
}
|
|
#else
|
|
template <std::size_t I, bool Dummy = true>
|
|
struct get_alt_impl
|
|
{
|
|
template <typename V>
|
|
inline constexpr AUTO_REFREF operator()(V&& v) const
|
|
AUTO_REFREF_RETURN(get_alt_impl<I - 1>{}(lib::forward<V>(v).tail_))
|
|
};
|
|
|
|
template <bool Dummy>
|
|
struct get_alt_impl<0, Dummy>
|
|
{
|
|
template <typename V>
|
|
inline constexpr AUTO_REFREF operator()(V&& v) const
|
|
AUTO_REFREF_RETURN(lib::forward<V>(v).head_)
|
|
};
|
|
|
|
template <typename V, std::size_t I>
|
|
inline static constexpr AUTO_REFREF get_alt(V&& v, ::std::in_place_index_t<I>)
|
|
AUTO_REFREF_RETURN(get_alt_impl<I>{}(lib::forward<V>(v)))
|
|
#endif
|
|
};
|
|
|
|
struct base
|
|
{
|
|
template <std::size_t I, typename V>
|
|
inline static constexpr AUTO_REFREF get_alt(V&& v)
|
|
AUTO_REFREF_RETURN(recursive_union::get_alt(lib::forward<V>(v).data_,
|
|
::std::in_place_index_t<I>{}))
|
|
};
|
|
|
|
struct variant
|
|
{
|
|
template <std::size_t I, typename V>
|
|
inline static constexpr AUTO_REFREF get_alt(V&& v)
|
|
AUTO_REFREF_RETURN(base::get_alt<I>(lib::forward<V>(v).impl_))
|
|
};
|
|
|
|
} // namespace access
|
|
|
|
namespace visitation
|
|
{
|
|
struct base
|
|
{
|
|
private:
|
|
template <typename T>
|
|
inline static constexpr const T& at(const T& elem)
|
|
{
|
|
return elem;
|
|
}
|
|
|
|
template <typename T, std::size_t N, typename... Is>
|
|
inline static constexpr const lib::remove_all_extents_t<T>& at(const lib::array<T, N>& elems,
|
|
std::size_t i, Is... is)
|
|
{
|
|
return at(elems[i], is...);
|
|
}
|
|
|
|
template <typename F, typename... Fs>
|
|
inline static constexpr int visit_visitor_return_type_check()
|
|
{
|
|
static_assert(all(std::is_same<F, Fs>::value...),
|
|
"`mpark::visit` requires the visitor to have a single "
|
|
"return type.");
|
|
return 0;
|
|
}
|
|
|
|
template <typename... Fs>
|
|
inline static constexpr lib::array<lib::common_type_t<lib::decay_t<Fs>...>, sizeof...(Fs)>
|
|
make_farray(Fs&&... fs)
|
|
{
|
|
using result = lib::array<lib::common_type_t<lib::decay_t<Fs>...>, sizeof...(Fs)>;
|
|
return visit_visitor_return_type_check<lib::decay_t<Fs>...>(),
|
|
result{{lib::forward<Fs>(fs)...}};
|
|
}
|
|
|
|
template <std::size_t... Is>
|
|
struct dispatcher
|
|
{
|
|
template <typename F, typename... Vs>
|
|
struct impl
|
|
{
|
|
inline static constexpr DECLTYPE_AUTO dispatch(F f, Vs... vs)
|
|
DECLTYPE_AUTO_RETURN(lib::invoke(static_cast<F>(f),
|
|
access::base::get_alt<Is>(static_cast<Vs>(vs))...))
|
|
};
|
|
};
|
|
|
|
template <typename F, typename... Vs, std::size_t... Is>
|
|
inline static constexpr AUTO make_dispatch(lib::index_sequence<Is...>)
|
|
AUTO_RETURN(&dispatcher<Is...>::template impl<F, Vs...>::dispatch)
|
|
|
|
template <std::size_t I, typename F, typename... Vs>
|
|
inline static constexpr AUTO make_fdiagonal_impl() AUTO_RETURN(
|
|
make_dispatch<F, Vs...>(lib::index_sequence<lib::indexed_type<I, Vs>::value...>{}))
|
|
|
|
template <typename F, typename... Vs, std::size_t... Is>
|
|
inline static constexpr AUTO make_fdiagonal_impl(lib::index_sequence<Is...>)
|
|
AUTO_RETURN(make_farray(make_fdiagonal_impl<Is, F, Vs...>()...))
|
|
|
|
template <typename F, typename V, typename... Vs>
|
|
inline static constexpr /* auto * */ auto make_fdiagonal()
|
|
-> decltype(make_fdiagonal_impl<F, V, Vs...>(
|
|
lib::make_index_sequence<lib::decay_t<V>::size()>{}))
|
|
{
|
|
static_assert(all((lib::decay_t<V>::size() == lib::decay_t<Vs>::size())...),
|
|
"all of the variants must be the same size.");
|
|
return make_fdiagonal_impl<F, V, Vs...>(lib::make_index_sequence<lib::decay_t<V>::size()>{});
|
|
}
|
|
|
|
#ifdef MPARK_RETURN_TYPE_DEDUCTION
|
|
template <typename F, typename... Vs, std::size_t... Is>
|
|
inline static constexpr auto make_fmatrix_impl(lib::index_sequence<Is...> is)
|
|
{
|
|
return make_dispatch<F, Vs...>(is);
|
|
}
|
|
|
|
template <typename F, typename... Vs, std::size_t... Is, std::size_t... Js, typename... Ls>
|
|
inline static constexpr auto make_fmatrix_impl(lib::index_sequence<Is...>,
|
|
lib::index_sequence<Js...>, Ls... ls)
|
|
{
|
|
return make_farray(make_fmatrix_impl<F, Vs...>(lib::index_sequence<Is..., Js>{}, ls...)...);
|
|
}
|
|
|
|
template <typename F, typename... Vs>
|
|
inline static constexpr auto make_fmatrix()
|
|
{
|
|
return make_fmatrix_impl<F, Vs...>(lib::index_sequence<>{},
|
|
lib::make_index_sequence<lib::decay_t<Vs>::size()>{}...);
|
|
}
|
|
#else
|
|
template <typename F, typename... Vs>
|
|
struct make_fmatrix_impl
|
|
{
|
|
template <typename...>
|
|
struct impl;
|
|
|
|
template <std::size_t... Is>
|
|
struct impl<lib::index_sequence<Is...>>
|
|
{
|
|
inline constexpr AUTO operator()() const
|
|
AUTO_RETURN(make_dispatch<F, Vs...>(lib::index_sequence<Is...>{}))
|
|
};
|
|
|
|
template <std::size_t... Is, std::size_t... Js, typename... Ls>
|
|
struct impl<lib::index_sequence<Is...>, lib::index_sequence<Js...>, Ls...>
|
|
{
|
|
inline constexpr AUTO operator()() const
|
|
AUTO_RETURN(make_farray(impl<lib::index_sequence<Is..., Js>, Ls...>{}()...))
|
|
};
|
|
};
|
|
|
|
template <typename F, typename... Vs>
|
|
inline static constexpr AUTO make_fmatrix()
|
|
AUTO_RETURN(
|
|
typename make_fmatrix_impl<F, Vs...>::template impl<
|
|
lib::index_sequence<>,
|
|
lib::make_index_sequence<lib::decay_t<Vs>::size()>...>{}())
|
|
#endif
|
|
|
|
public:
|
|
template <typename Visitor, typename... Vs>
|
|
inline static constexpr DECLTYPE_AUTO visit_alt_at(std::size_t index, Visitor&& visitor,
|
|
Vs&&... vs)
|
|
DECLTYPE_AUTO_RETURN(
|
|
at(make_fdiagonal<Visitor&&, decltype(as_base(lib::forward<Vs>(vs)))...>(),
|
|
index)(lib::forward<Visitor>(visitor), as_base(lib::forward<Vs>(vs))...))
|
|
|
|
template <typename Visitor, typename... Vs>
|
|
inline static constexpr DECLTYPE_AUTO
|
|
visit_alt(Visitor&& visitor, Vs&&... vs) DECLTYPE_AUTO_RETURN(
|
|
at(make_fmatrix<Visitor&&, decltype(as_base(lib::forward<Vs>(vs)))...>(),
|
|
vs.index()...)(lib::forward<Visitor>(visitor), as_base(lib::forward<Vs>(vs))...))
|
|
};
|
|
|
|
struct variant
|
|
{
|
|
private:
|
|
template <typename Visitor, typename... Values>
|
|
struct visit_exhaustive_visitor_check
|
|
{
|
|
static_assert(lib::is_invocable<Visitor, Values...>::value,
|
|
"`mpark::visit` requires the visitor to be exhaustive.");
|
|
|
|
#ifdef _MSC_VER
|
|
#pragma warning(push)
|
|
#pragma warning(disable : 4100)
|
|
#endif
|
|
inline constexpr DECLTYPE_AUTO operator()(Visitor&& visitor, Values&&... values) const
|
|
DECLTYPE_AUTO_RETURN(lib::invoke(lib::forward<Visitor>(visitor),
|
|
lib::forward<Values>(values)...))
|
|
#ifdef _MSC_VER
|
|
#pragma warning(pop)
|
|
#endif
|
|
};
|
|
|
|
template <typename Visitor>
|
|
struct value_visitor
|
|
{
|
|
Visitor&& visitor_;
|
|
|
|
template <typename... Alts>
|
|
inline constexpr DECLTYPE_AUTO operator()(Alts&&... alts) const DECLTYPE_AUTO_RETURN(
|
|
visit_exhaustive_visitor_check<Visitor, decltype((lib::forward<Alts>(alts).value))...>{}(
|
|
lib::forward<Visitor>(visitor_), lib::forward<Alts>(alts).value...))
|
|
};
|
|
|
|
template <typename Visitor>
|
|
inline static constexpr AUTO make_value_visitor(Visitor&& visitor)
|
|
AUTO_RETURN(value_visitor<Visitor>{lib::forward<Visitor>(visitor)})
|
|
|
|
public
|
|
: template <typename Visitor, typename... Vs>
|
|
inline static constexpr DECLTYPE_AUTO
|
|
visit_alt_at(std::size_t index, Visitor&& visitor, Vs&&... vs)
|
|
DECLTYPE_AUTO_RETURN(base::visit_alt_at(index, lib::forward<Visitor>(visitor),
|
|
lib::forward<Vs>(vs).impl_...))
|
|
|
|
template <typename Visitor, typename... Vs>
|
|
inline static constexpr DECLTYPE_AUTO visit_alt(Visitor&& visitor, Vs&&... vs)
|
|
DECLTYPE_AUTO_RETURN(base::visit_alt(lib::forward<Visitor>(visitor),
|
|
lib::forward<Vs>(vs).impl_...))
|
|
|
|
template <typename Visitor, typename... Vs>
|
|
inline static constexpr DECLTYPE_AUTO
|
|
visit_value_at(std::size_t index, Visitor&& visitor, Vs&&... vs)
|
|
DECLTYPE_AUTO_RETURN(visit_alt_at(index,
|
|
make_value_visitor(lib::forward<Visitor>(visitor)),
|
|
lib::forward<Vs>(vs)...))
|
|
|
|
template <typename Visitor, typename... Vs>
|
|
inline static constexpr DECLTYPE_AUTO
|
|
visit_value(Visitor&& visitor, Vs&&... vs)
|
|
DECLTYPE_AUTO_RETURN(visit_alt(make_value_visitor(lib::forward<Visitor>(visitor)),
|
|
lib::forward<Vs>(vs)...))
|
|
};
|
|
|
|
} // namespace visitation
|
|
|
|
template <std::size_t Index, typename T>
|
|
struct alt
|
|
{
|
|
using value_type = T;
|
|
|
|
#ifdef _MSC_VER
|
|
#pragma warning(push)
|
|
#pragma warning(disable : 4244)
|
|
#endif
|
|
template <typename... Args>
|
|
inline explicit constexpr alt(::std::in_place_t, Args&&... args)
|
|
: value(lib::forward<Args>(args)...)
|
|
{
|
|
}
|
|
#ifdef _MSC_VER
|
|
#pragma warning(pop)
|
|
#endif
|
|
|
|
T value;
|
|
};
|
|
|
|
template <Trait DestructibleTrait, std::size_t Index, typename... Ts>
|
|
union recursive_union;
|
|
|
|
template <Trait DestructibleTrait, std::size_t Index>
|
|
union recursive_union<DestructibleTrait, Index>
|
|
{
|
|
};
|
|
|
|
#define MPARK_VARIANT_RECURSIVE_UNION(destructible_trait, destructor) \
|
|
template <std::size_t Index, typename T, typename... Ts> \
|
|
union recursive_union<destructible_trait, Index, T, Ts...> \
|
|
{ \
|
|
public: \
|
|
inline explicit constexpr recursive_union(valueless_t) noexcept : dummy_{} {} \
|
|
template <typename... Args> \
|
|
inline explicit constexpr recursive_union(::std::in_place_index_t<0>, Args&&... args) \
|
|
: head_(::std::in_place_t{}, lib::forward<Args>(args)...) \
|
|
{ \
|
|
} \
|
|
\
|
|
template <std::size_t I, typename... Args> \
|
|
inline explicit constexpr recursive_union(::std::in_place_index_t<I>, Args&&... args) \
|
|
: tail_(::std::in_place_index_t<I - 1>{}, lib::forward<Args>(args)...) \
|
|
{ \
|
|
} \
|
|
\
|
|
recursive_union(const recursive_union&) = default; \
|
|
recursive_union(recursive_union&&) = default; \
|
|
\
|
|
destructor \
|
|
\
|
|
recursive_union& \
|
|
operator=(const recursive_union&) = default; \
|
|
recursive_union& operator=(recursive_union&&) = default; \
|
|
\
|
|
private: \
|
|
char dummy_; \
|
|
alt<Index, T> head_; \
|
|
recursive_union<destructible_trait, Index + 1, Ts...> tail_; \
|
|
\
|
|
friend struct access::recursive_union; \
|
|
}
|
|
|
|
MPARK_VARIANT_RECURSIVE_UNION(Trait::TriviallyAvailable, ~recursive_union() = default;);
|
|
MPARK_VARIANT_RECURSIVE_UNION(Trait::Available, ~recursive_union(){});
|
|
MPARK_VARIANT_RECURSIVE_UNION(Trait::Unavailable, ~recursive_union() = delete;);
|
|
|
|
#undef MPARK_VARIANT_RECURSIVE_UNION
|
|
|
|
using index_t = unsigned int;
|
|
|
|
template <Trait DestructibleTrait, typename... Ts>
|
|
class base
|
|
{
|
|
public:
|
|
inline explicit constexpr base(valueless_t tag) noexcept : data_(tag),
|
|
index_(static_cast<index_t>(-1))
|
|
{
|
|
}
|
|
|
|
template <std::size_t I, typename... Args>
|
|
inline explicit constexpr base(::std::in_place_index_t<I>, Args&&... args)
|
|
: data_(::std::in_place_index_t<I>{}, lib::forward<Args>(args)...), index_(I)
|
|
{
|
|
}
|
|
|
|
inline constexpr bool valueless_by_exception() const noexcept
|
|
{
|
|
return index_ == static_cast<index_t>(-1);
|
|
}
|
|
|
|
inline constexpr std::size_t index() const noexcept
|
|
{
|
|
return valueless_by_exception() ? variant_npos : index_;
|
|
}
|
|
|
|
protected:
|
|
friend inline constexpr base& as_base(base& b) { return b; }
|
|
friend inline constexpr const base& as_base(const base& b) { return b; }
|
|
friend inline constexpr base&& as_base(base&& b) { return lib::move(b); }
|
|
friend inline constexpr const base&& as_base(const base&& b) { return lib::move(b); }
|
|
inline static constexpr std::size_t size() { return sizeof...(Ts); }
|
|
recursive_union<DestructibleTrait, 0, Ts...> data_;
|
|
index_t index_;
|
|
|
|
friend struct access::base;
|
|
friend struct visitation::base;
|
|
};
|
|
|
|
struct dtor
|
|
{
|
|
#ifdef _MSC_VER
|
|
#pragma warning(push)
|
|
#pragma warning(disable : 4100)
|
|
#endif
|
|
template <typename Alt>
|
|
inline void operator()(Alt& alt) const noexcept
|
|
{
|
|
alt.~Alt();
|
|
}
|
|
#ifdef _MSC_VER
|
|
#pragma warning(pop)
|
|
#endif
|
|
};
|
|
|
|
#if defined(_MSC_VER) && _MSC_VER < 1910
|
|
#define INHERITING_CTOR(type, base) \
|
|
template <typename... Args> \
|
|
inline explicit constexpr type(Args&&... args) : base(lib::forward<Args>(args)...) \
|
|
{ \
|
|
}
|
|
#else
|
|
#define INHERITING_CTOR(type, base) using base::base;
|
|
#endif
|
|
|
|
template <typename Traits, Trait = Traits::destructible_trait>
|
|
class destructor;
|
|
|
|
#define MPARK_VARIANT_DESTRUCTOR(destructible_trait, definition, destroy) \
|
|
template <typename... Ts> \
|
|
class destructor<traits<Ts...>, destructible_trait> : public base<destructible_trait, Ts...> \
|
|
{ \
|
|
using super = base<destructible_trait, Ts...>; \
|
|
\
|
|
public: \
|
|
INHERITING_CTOR(destructor, super) \
|
|
using super::operator=; \
|
|
\
|
|
destructor(const destructor&) = default; \
|
|
destructor(destructor&&) = default; \
|
|
definition destructor& operator=(const destructor&) = default; \
|
|
destructor& operator=(destructor&&) = default; \
|
|
\
|
|
protected: \
|
|
destroy \
|
|
}
|
|
|
|
MPARK_VARIANT_DESTRUCTOR(Trait::TriviallyAvailable, ~destructor() = default;
|
|
, inline void destroy() noexcept {
|
|
this->index_ = static_cast<index_t>(-1);
|
|
});
|
|
|
|
MPARK_VARIANT_DESTRUCTOR(Trait::Available, ~destructor() { destroy(); },
|
|
inline void destroy() noexcept {
|
|
if (!this->valueless_by_exception())
|
|
{
|
|
visitation::base::visit_alt(dtor{}, *this);
|
|
}
|
|
this->index_ = static_cast<index_t>(-1);
|
|
});
|
|
|
|
MPARK_VARIANT_DESTRUCTOR(Trait::Unavailable, ~destructor() = delete;
|
|
, inline void destroy() noexcept = delete;);
|
|
|
|
#undef MPARK_VARIANT_DESTRUCTOR
|
|
|
|
template <typename Traits>
|
|
class constructor : public destructor<Traits>
|
|
{
|
|
using super = destructor<Traits>;
|
|
|
|
public:
|
|
INHERITING_CTOR(constructor, super)
|
|
using super::operator=;
|
|
|
|
protected:
|
|
#ifndef MPARK_GENERIC_LAMBDAS
|
|
struct ctor
|
|
{
|
|
template <typename LhsAlt, typename RhsAlt>
|
|
inline void operator()(LhsAlt& lhs_alt, RhsAlt&& rhs_alt) const
|
|
{
|
|
constructor::construct_alt(lhs_alt, lib::forward<RhsAlt>(rhs_alt).value);
|
|
}
|
|
};
|
|
#endif
|
|
|
|
template <std::size_t I, typename T, typename... Args>
|
|
inline static T& construct_alt(alt<I, T>& a, Args&&... args)
|
|
{
|
|
::new (static_cast<void*>(lib::addressof(a)))
|
|
alt<I, T>(::std::in_place_t{}, lib::forward<Args>(args)...);
|
|
return a.value;
|
|
}
|
|
|
|
template <typename Rhs>
|
|
inline static void generic_construct(constructor& lhs, Rhs&& rhs)
|
|
{
|
|
lhs.destroy();
|
|
if (!rhs.valueless_by_exception())
|
|
{
|
|
visitation::base::visit_alt_at(rhs.index(),
|
|
#ifdef MPARK_GENERIC_LAMBDAS
|
|
[](auto& lhs_alt, auto&& rhs_alt) {
|
|
constructor::construct_alt(
|
|
lhs_alt, lib::forward<decltype(rhs_alt)>(rhs_alt).value);
|
|
}
|
|
#else
|
|
ctor {}
|
|
#endif
|
|
,
|
|
lhs, lib::forward<Rhs>(rhs));
|
|
lhs.index_ = rhs.index_;
|
|
}
|
|
}
|
|
};
|
|
|
|
template <typename Traits, Trait = Traits::move_constructible_trait>
|
|
class move_constructor;
|
|
|
|
#define MPARK_VARIANT_MOVE_CONSTRUCTOR(move_constructible_trait, definition) \
|
|
template <typename... Ts> \
|
|
class move_constructor<traits<Ts...>, move_constructible_trait> \
|
|
: public constructor<traits<Ts...>> \
|
|
{ \
|
|
using super = constructor<traits<Ts...>>; \
|
|
\
|
|
public: \
|
|
INHERITING_CTOR(move_constructor, super) \
|
|
using super::operator=; \
|
|
\
|
|
move_constructor(const move_constructor&) = default; \
|
|
definition ~move_constructor() = default; \
|
|
move_constructor& operator=(const move_constructor&) = default; \
|
|
move_constructor& operator=(move_constructor&&) = default; \
|
|
}
|
|
|
|
MPARK_VARIANT_MOVE_CONSTRUCTOR(Trait::TriviallyAvailable,
|
|
move_constructor(move_constructor&& that) = default;);
|
|
|
|
MPARK_VARIANT_MOVE_CONSTRUCTOR(Trait::Available,
|
|
move_constructor(move_constructor&& that) noexcept(
|
|
all(std::is_nothrow_move_constructible<Ts>::value...))
|
|
: move_constructor(valueless_t{}) {
|
|
this->generic_construct(*this, lib::move(that));
|
|
});
|
|
|
|
MPARK_VARIANT_MOVE_CONSTRUCTOR(Trait::Unavailable, move_constructor(move_constructor&&) = delete;);
|
|
|
|
#undef MPARK_VARIANT_MOVE_CONSTRUCTOR
|
|
|
|
template <typename Traits, Trait = Traits::copy_constructible_trait>
|
|
class copy_constructor;
|
|
|
|
#define MPARK_VARIANT_COPY_CONSTRUCTOR(copy_constructible_trait, definition) \
|
|
template <typename... Ts> \
|
|
class copy_constructor<traits<Ts...>, copy_constructible_trait> \
|
|
: public move_constructor<traits<Ts...>> \
|
|
{ \
|
|
using super = move_constructor<traits<Ts...>>; \
|
|
\
|
|
public: \
|
|
INHERITING_CTOR(copy_constructor, super) \
|
|
using super::operator=; \
|
|
\
|
|
definition copy_constructor(copy_constructor&&) = default; \
|
|
~copy_constructor() = default; \
|
|
copy_constructor& operator=(const copy_constructor&) = default; \
|
|
copy_constructor& operator=(copy_constructor&&) = default; \
|
|
}
|
|
|
|
MPARK_VARIANT_COPY_CONSTRUCTOR(Trait::TriviallyAvailable,
|
|
copy_constructor(const copy_constructor& that) = default;);
|
|
|
|
MPARK_VARIANT_COPY_CONSTRUCTOR(Trait::Available, copy_constructor(const copy_constructor& that)
|
|
: copy_constructor(valueless_t{}) {
|
|
this->generic_construct(*this, that);
|
|
});
|
|
|
|
MPARK_VARIANT_COPY_CONSTRUCTOR(Trait::Unavailable,
|
|
copy_constructor(const copy_constructor&) = delete;);
|
|
|
|
#undef MPARK_VARIANT_COPY_CONSTRUCTOR
|
|
|
|
template <typename Traits>
|
|
class assignment : public copy_constructor<Traits>
|
|
{
|
|
using super = copy_constructor<Traits>;
|
|
|
|
public:
|
|
INHERITING_CTOR(assignment, super)
|
|
using super::operator=;
|
|
|
|
template <std::size_t I, typename... Args>
|
|
inline /* auto & */ auto emplace(Args&&... args)
|
|
-> decltype(this->construct_alt(access::base::get_alt<I>(*this), lib::forward<Args>(args)...))
|
|
{
|
|
this->destroy();
|
|
auto& result =
|
|
this->construct_alt(access::base::get_alt<I>(*this), lib::forward<Args>(args)...);
|
|
this->index_ = I;
|
|
return result;
|
|
}
|
|
|
|
protected:
|
|
#ifndef MPARK_GENERIC_LAMBDAS
|
|
template <typename That>
|
|
struct assigner
|
|
{
|
|
template <typename ThisAlt, typename ThatAlt>
|
|
inline void operator()(ThisAlt& this_alt, ThatAlt&& that_alt) const
|
|
{
|
|
self->assign_alt(this_alt, lib::forward<ThatAlt>(that_alt).value,
|
|
std::is_lvalue_reference<That>{});
|
|
}
|
|
assignment* self;
|
|
};
|
|
#endif
|
|
|
|
template <bool CopyAssign, std::size_t I, typename T, typename Arg>
|
|
inline void assign_alt(alt<I, T>& a, Arg&& arg, lib::bool_constant<CopyAssign> tag)
|
|
{
|
|
if (this->index() == I)
|
|
{
|
|
#ifdef _MSC_VER
|
|
#pragma warning(push)
|
|
#pragma warning(disable : 4244)
|
|
#endif
|
|
a.value = lib::forward<Arg>(arg);
|
|
#ifdef _MSC_VER
|
|
#pragma warning(pop)
|
|
#endif
|
|
}
|
|
else
|
|
{
|
|
struct
|
|
{
|
|
void operator()(std::true_type) const { this_->emplace<I>(T(lib::forward<Arg>(arg_))); }
|
|
void operator()(std::false_type) const { this_->emplace<I>(lib::forward<Arg>(arg_)); }
|
|
assignment* this_;
|
|
Arg&& arg_;
|
|
} impl{this, lib::forward<Arg>(arg)};
|
|
impl(tag);
|
|
}
|
|
}
|
|
|
|
template <typename That>
|
|
inline void generic_assign(That&& that)
|
|
{
|
|
if (this->valueless_by_exception() && that.valueless_by_exception())
|
|
{
|
|
// do nothing.
|
|
}
|
|
else if (that.valueless_by_exception())
|
|
{
|
|
this->destroy();
|
|
}
|
|
else
|
|
{
|
|
visitation::base::visit_alt_at(
|
|
that.index(),
|
|
#ifdef MPARK_GENERIC_LAMBDAS
|
|
[this](auto& this_alt, auto&& that_alt) {
|
|
this->assign_alt(this_alt, lib::forward<decltype(that_alt)>(that_alt).value,
|
|
std::is_lvalue_reference<That>{});
|
|
}
|
|
#else
|
|
assigner<That> { this }
|
|
#endif
|
|
,
|
|
*this, lib::forward<That>(that));
|
|
}
|
|
}
|
|
};
|
|
|
|
template <typename Traits, Trait = Traits::move_assignable_trait>
|
|
class move_assignment;
|
|
|
|
#define MPARK_VARIANT_MOVE_ASSIGNMENT(move_assignable_trait, definition) \
|
|
template <typename... Ts> \
|
|
class move_assignment<traits<Ts...>, move_assignable_trait> : public assignment<traits<Ts...>> \
|
|
{ \
|
|
using super = assignment<traits<Ts...>>; \
|
|
\
|
|
public: \
|
|
INHERITING_CTOR(move_assignment, super) \
|
|
using super::operator=; \
|
|
\
|
|
move_assignment(const move_assignment&) = default; \
|
|
move_assignment(move_assignment&&) = default; \
|
|
~move_assignment() = default; \
|
|
move_assignment& operator=(const move_assignment&) = default; \
|
|
definition \
|
|
}
|
|
|
|
MPARK_VARIANT_MOVE_ASSIGNMENT(Trait::TriviallyAvailable,
|
|
move_assignment& operator=(move_assignment&& that) = default;);
|
|
|
|
MPARK_VARIANT_MOVE_ASSIGNMENT(Trait::Available,
|
|
move_assignment& operator=(move_assignment&& that) noexcept(
|
|
all((std::is_nothrow_move_constructible<Ts>::value &&
|
|
std::is_nothrow_move_assignable<Ts>::value)...)) {
|
|
this->generic_assign(lib::move(that));
|
|
return *this;
|
|
});
|
|
|
|
MPARK_VARIANT_MOVE_ASSIGNMENT(Trait::Unavailable,
|
|
move_assignment& operator=(move_assignment&&) = delete;);
|
|
|
|
#undef MPARK_VARIANT_MOVE_ASSIGNMENT
|
|
|
|
template <typename Traits, Trait = Traits::copy_assignable_trait>
|
|
class copy_assignment;
|
|
|
|
#define MPARK_VARIANT_COPY_ASSIGNMENT(copy_assignable_trait, definition) \
|
|
template <typename... Ts> \
|
|
class copy_assignment<traits<Ts...>, copy_assignable_trait> \
|
|
: public move_assignment<traits<Ts...>> \
|
|
{ \
|
|
using super = move_assignment<traits<Ts...>>; \
|
|
\
|
|
public: \
|
|
INHERITING_CTOR(copy_assignment, super) \
|
|
using super::operator=; \
|
|
\
|
|
copy_assignment(const copy_assignment&) = default; \
|
|
copy_assignment(copy_assignment&&) = default; \
|
|
~copy_assignment() = default; \
|
|
definition copy_assignment& operator=(copy_assignment&&) = default; \
|
|
}
|
|
|
|
MPARK_VARIANT_COPY_ASSIGNMENT(Trait::TriviallyAvailable,
|
|
copy_assignment& operator=(const copy_assignment& that) = default;);
|
|
|
|
MPARK_VARIANT_COPY_ASSIGNMENT(Trait::Available,
|
|
copy_assignment& operator=(const copy_assignment& that) {
|
|
this->generic_assign(that);
|
|
return *this;
|
|
});
|
|
|
|
MPARK_VARIANT_COPY_ASSIGNMENT(Trait::Unavailable,
|
|
copy_assignment& operator=(const copy_assignment&) = delete;);
|
|
|
|
#undef MPARK_VARIANT_COPY_ASSIGNMENT
|
|
|
|
template <typename... Ts>
|
|
class impl : public copy_assignment<traits<Ts...>>
|
|
{
|
|
using super = copy_assignment<traits<Ts...>>;
|
|
|
|
public:
|
|
INHERITING_CTOR(impl, super)
|
|
using super::operator=;
|
|
|
|
template <std::size_t I, typename Arg>
|
|
inline void assign(Arg&& arg)
|
|
{
|
|
this->assign_alt(access::base::get_alt<I>(*this), lib::forward<Arg>(arg), std::false_type{});
|
|
}
|
|
|
|
inline void swap(impl& that)
|
|
{
|
|
if (this->valueless_by_exception() && that.valueless_by_exception())
|
|
{
|
|
// do nothing.
|
|
}
|
|
else if (this->index() == that.index())
|
|
{
|
|
visitation::base::visit_alt_at(this->index(),
|
|
#ifdef MPARK_GENERIC_LAMBDAS
|
|
[](auto& this_alt, auto& that_alt) {
|
|
using std::swap;
|
|
swap(this_alt.value, that_alt.value);
|
|
}
|
|
#else
|
|
swapper {}
|
|
#endif
|
|
,
|
|
*this, that);
|
|
}
|
|
else
|
|
{
|
|
impl* lhs = this;
|
|
impl* rhs = lib::addressof(that);
|
|
if (lhs->move_nothrow() && !rhs->move_nothrow())
|
|
{
|
|
std::swap(lhs, rhs);
|
|
}
|
|
impl tmp(lib::move(*rhs));
|
|
#ifdef MPARK_EXCEPTIONS
|
|
// EXTENSION: When the move construction of `lhs` into `rhs` throws
|
|
// and `tmp` is nothrow move constructible then we move `tmp` back
|
|
// into `rhs` and provide the strong exception safety guarantee.
|
|
try
|
|
{
|
|
this->generic_construct(*rhs, lib::move(*lhs));
|
|
}
|
|
catch (...)
|
|
{
|
|
if (tmp.move_nothrow())
|
|
{
|
|
this->generic_construct(*rhs, lib::move(tmp));
|
|
}
|
|
throw;
|
|
}
|
|
#else
|
|
this->generic_construct(*rhs, lib::move(*lhs));
|
|
#endif
|
|
this->generic_construct(*lhs, lib::move(tmp));
|
|
}
|
|
}
|
|
|
|
private:
|
|
#ifndef MPARK_GENERIC_LAMBDAS
|
|
struct swapper
|
|
{
|
|
template <typename ThisAlt, typename ThatAlt>
|
|
inline void operator()(ThisAlt& this_alt, ThatAlt& that_alt) const
|
|
{
|
|
using std::swap;
|
|
swap(this_alt.value, that_alt.value);
|
|
}
|
|
};
|
|
#endif
|
|
|
|
inline constexpr bool move_nothrow() const
|
|
{
|
|
return this->valueless_by_exception() ||
|
|
lib::array<bool, sizeof...(Ts)>{
|
|
{std::is_nothrow_move_constructible<Ts>::value...}}[this->index()];
|
|
}
|
|
};
|
|
|
|
template <typename... Ts>
|
|
struct overload;
|
|
|
|
template <>
|
|
struct overload<>
|
|
{
|
|
void operator()() const {}
|
|
};
|
|
|
|
template <typename T, typename... Ts>
|
|
struct overload<T, Ts...> : overload<Ts...>
|
|
{
|
|
using overload<Ts...>::operator();
|
|
lib::identity<T> operator()(T) const { return {}; }
|
|
};
|
|
|
|
template <typename T, typename... Ts>
|
|
using best_match_t = typename lib::invoke_result_t<overload<Ts...>, T&&>::type;
|
|
|
|
} // detail
|
|
|
|
template <typename... Ts>
|
|
class variant
|
|
{
|
|
static_assert(0 < sizeof...(Ts), "variant must consist of at least one alternative.");
|
|
|
|
static_assert(lib::all<!std::is_array<Ts>::value...>::value,
|
|
"variant can not have an array type as an alternative.");
|
|
|
|
static_assert(lib::all<!std::is_reference<Ts>::value...>::value,
|
|
"variant can not have a reference type as an alternative.");
|
|
|
|
static_assert(lib::all<!std::is_void<Ts>::value...>::value,
|
|
"variant can not have a void type as an alternative.");
|
|
|
|
public:
|
|
template <typename Front = lib::type_pack_element_t<0, Ts...>,
|
|
lib::enable_if_t<std::is_default_constructible<Front>::value, int> = 0>
|
|
inline constexpr variant() noexcept(std::is_nothrow_default_constructible<Front>::value)
|
|
: impl_(::std::in_place_index_t<0>{})
|
|
{
|
|
}
|
|
|
|
variant(const variant&) = default;
|
|
variant(variant&&) = default;
|
|
|
|
template <typename Arg,
|
|
lib::enable_if_t<!std::is_same<lib::decay_t<Arg>, variant>::value, int> = 0,
|
|
typename T = detail::best_match_t<Arg, Ts...>,
|
|
std::size_t I = detail::find_index_sfinae<T, Ts...>::value,
|
|
lib::enable_if_t<std::is_constructible<T, Arg>::value, int> = 0>
|
|
inline constexpr variant(Arg&& arg) noexcept(std::is_nothrow_constructible<T, Arg>::value)
|
|
: impl_(::std::in_place_index_t<I>{}, lib::forward<Arg>(arg))
|
|
{
|
|
}
|
|
|
|
template <std::size_t I, typename... Args, typename T = lib::type_pack_element_t<I, Ts...>,
|
|
lib::enable_if_t<std::is_constructible<T, Args...>::value, int> = 0>
|
|
inline explicit constexpr variant(::std::in_place_index_t<I>, Args&&... args) noexcept(
|
|
std::is_nothrow_constructible<T, Args...>::value)
|
|
: impl_(::std::in_place_index_t<I>{}, lib::forward<Args>(args)...)
|
|
{
|
|
}
|
|
|
|
template <std::size_t I, typename Up, typename... Args,
|
|
typename T = lib::type_pack_element_t<I, Ts...>,
|
|
lib::enable_if_t<std::is_constructible<T, std::initializer_list<Up>&, Args...>::value,
|
|
int> = 0>
|
|
inline explicit constexpr variant(
|
|
::std::in_place_index_t<I>, std::initializer_list<Up> il,
|
|
Args&&... args) noexcept(std::is_nothrow_constructible<T, std::initializer_list<Up>&,
|
|
Args...>::value)
|
|
: impl_(::std::in_place_index_t<I>{}, il, lib::forward<Args>(args)...)
|
|
{
|
|
}
|
|
|
|
template <typename T, typename... Args,
|
|
std::size_t I = detail::find_index_sfinae<T, Ts...>::value,
|
|
lib::enable_if_t<std::is_constructible<T, Args...>::value, int> = 0>
|
|
inline explicit constexpr variant(::std::in_place_type_t<T>, Args&&... args) noexcept(
|
|
std::is_nothrow_constructible<T, Args...>::value)
|
|
: impl_(::std::in_place_index_t<I>{}, lib::forward<Args>(args)...)
|
|
{
|
|
}
|
|
|
|
template <typename T, typename Up, typename... Args,
|
|
std::size_t I = detail::find_index_sfinae<T, Ts...>::value,
|
|
lib::enable_if_t<std::is_constructible<T, std::initializer_list<Up>&, Args...>::value,
|
|
int> = 0>
|
|
inline explicit constexpr variant(
|
|
::std::in_place_type_t<T>, std::initializer_list<Up> il,
|
|
Args&&... args) noexcept(std::is_nothrow_constructible<T, std::initializer_list<Up>&,
|
|
Args...>::value)
|
|
: impl_(::std::in_place_index_t<I>{}, il, lib::forward<Args>(args)...)
|
|
{
|
|
}
|
|
|
|
~variant() = default;
|
|
|
|
variant& operator=(const variant&) = default;
|
|
variant& operator=(variant&&) = default;
|
|
|
|
template <
|
|
typename Arg, lib::enable_if_t<!std::is_same<lib::decay_t<Arg>, variant>::value, int> = 0,
|
|
typename T = detail::best_match_t<Arg, Ts...>,
|
|
std::size_t I = detail::find_index_sfinae<T, Ts...>::value,
|
|
lib::enable_if_t<(std::is_assignable<T&, Arg>::value && std::is_constructible<T, Arg>::value),
|
|
int> = 0>
|
|
inline variant& operator=(Arg&& arg) noexcept((std::is_nothrow_assignable<T&, Arg>::value &&
|
|
std::is_nothrow_constructible<T, Arg>::value))
|
|
{
|
|
impl_.template assign<I>(lib::forward<Arg>(arg));
|
|
return *this;
|
|
}
|
|
|
|
template <std::size_t I, typename... Args, typename T = lib::type_pack_element_t<I, Ts...>,
|
|
lib::enable_if_t<std::is_constructible<T, Args...>::value, int> = 0>
|
|
inline T& emplace(Args&&... args)
|
|
{
|
|
return impl_.template emplace<I>(lib::forward<Args>(args)...);
|
|
}
|
|
|
|
template <std::size_t I, typename Up, typename... Args,
|
|
typename T = lib::type_pack_element_t<I, Ts...>,
|
|
lib::enable_if_t<std::is_constructible<T, std::initializer_list<Up>&, Args...>::value,
|
|
int> = 0>
|
|
inline T& emplace(std::initializer_list<Up> il, Args&&... args)
|
|
{
|
|
return impl_.template emplace<I>(il, lib::forward<Args>(args)...);
|
|
}
|
|
|
|
template <typename T, typename... Args,
|
|
std::size_t I = detail::find_index_sfinae<T, Ts...>::value,
|
|
lib::enable_if_t<std::is_constructible<T, Args...>::value, int> = 0>
|
|
inline T& emplace(Args&&... args)
|
|
{
|
|
return impl_.template emplace<I>(lib::forward<Args>(args)...);
|
|
}
|
|
|
|
template <typename T, typename Up, typename... Args,
|
|
std::size_t I = detail::find_index_sfinae<T, Ts...>::value,
|
|
lib::enable_if_t<std::is_constructible<T, std::initializer_list<Up>&, Args...>::value,
|
|
int> = 0>
|
|
inline T& emplace(std::initializer_list<Up> il, Args&&... args)
|
|
{
|
|
return impl_.template emplace<I>(il, lib::forward<Args>(args)...);
|
|
}
|
|
|
|
inline constexpr bool valueless_by_exception() const noexcept
|
|
{
|
|
return impl_.valueless_by_exception();
|
|
}
|
|
|
|
inline constexpr std::size_t index() const noexcept { return impl_.index(); }
|
|
template <bool Dummy = true,
|
|
lib::enable_if_t<lib::all<Dummy, (std::is_move_constructible<Ts>::value &&
|
|
lib::is_swappable<Ts>::value)...>::value,
|
|
int> = 0>
|
|
inline void
|
|
swap(variant& that) noexcept(lib::all<(std::is_nothrow_move_constructible<Ts>::value &&
|
|
lib::is_nothrow_swappable<Ts>::value)...>::value)
|
|
{
|
|
impl_.swap(that.impl_);
|
|
}
|
|
|
|
private:
|
|
detail::impl<Ts...> impl_;
|
|
|
|
friend struct detail::access::variant;
|
|
friend struct detail::visitation::variant;
|
|
};
|
|
|
|
template <std::size_t I, typename... Ts>
|
|
inline constexpr bool holds_alternative(const variant<Ts...>& v) noexcept
|
|
{
|
|
return v.index() == I;
|
|
}
|
|
|
|
template <typename T, typename... Ts>
|
|
inline constexpr bool holds_alternative(const variant<Ts...>& v) noexcept
|
|
{
|
|
return holds_alternative<detail::find_index_checked<T, Ts...>::value>(v);
|
|
}
|
|
|
|
namespace detail
|
|
{
|
|
template <std::size_t I, typename V>
|
|
struct generic_get_impl
|
|
{
|
|
constexpr generic_get_impl(int) {}
|
|
constexpr AUTO_REFREF operator()(V&& v) const
|
|
AUTO_REFREF_RETURN(access::variant::get_alt<I>(lib::forward<V>(v)).value)
|
|
};
|
|
|
|
template <std::size_t I, typename V>
|
|
inline constexpr AUTO_REFREF generic_get(V&& v) AUTO_REFREF_RETURN(generic_get_impl<I, V>(
|
|
holds_alternative<I>(v) ? 0 : (throw_bad_variant_access(), 0))(lib::forward<V>(v)))
|
|
} // namespace detail
|
|
|
|
template <std::size_t I, typename... Ts>
|
|
inline constexpr variant_alternative_t<I, variant<Ts...>>& get(variant<Ts...>& v)
|
|
{
|
|
return detail::generic_get<I>(v);
|
|
}
|
|
|
|
template <std::size_t I, typename... Ts>
|
|
inline constexpr variant_alternative_t<I, variant<Ts...>>&& get(variant<Ts...>&& v)
|
|
{
|
|
return detail::generic_get<I>(lib::move(v));
|
|
}
|
|
|
|
template <std::size_t I, typename... Ts>
|
|
inline constexpr const variant_alternative_t<I, variant<Ts...>>& get(const variant<Ts...>& v)
|
|
{
|
|
return detail::generic_get<I>(v);
|
|
}
|
|
|
|
template <std::size_t I, typename... Ts>
|
|
inline constexpr const variant_alternative_t<I, variant<Ts...>>&& get(const variant<Ts...>&& v)
|
|
{
|
|
return detail::generic_get<I>(lib::move(v));
|
|
}
|
|
|
|
template <typename T, typename... Ts>
|
|
inline constexpr T& get(variant<Ts...>& v)
|
|
{
|
|
return get<detail::find_index_checked<T, Ts...>::value>(v);
|
|
}
|
|
|
|
template <typename T, typename... Ts>
|
|
inline constexpr T&& get(variant<Ts...>&& v)
|
|
{
|
|
return get<detail::find_index_checked<T, Ts...>::value>(lib::move(v));
|
|
}
|
|
|
|
template <typename T, typename... Ts>
|
|
inline constexpr const T& get(const variant<Ts...>& v)
|
|
{
|
|
return get<detail::find_index_checked<T, Ts...>::value>(v);
|
|
}
|
|
|
|
template <typename T, typename... Ts>
|
|
inline constexpr const T&& get(const variant<Ts...>&& v)
|
|
{
|
|
return get<detail::find_index_checked<T, Ts...>::value>(lib::move(v));
|
|
}
|
|
|
|
namespace detail
|
|
{
|
|
template <std::size_t I, typename V>
|
|
inline constexpr /* auto * */ AUTO generic_get_if(V* v) noexcept AUTO_RETURN(
|
|
v&& holds_alternative<I>(*v) ? lib::addressof(access::variant::get_alt<I>(*v).value) : nullptr)
|
|
|
|
} // namespace detail
|
|
|
|
template <std::size_t I, typename... Ts>
|
|
inline constexpr lib::add_pointer_t<variant_alternative_t<I, variant<Ts...>>>
|
|
get_if(variant<Ts...>* v) noexcept
|
|
{
|
|
return detail::generic_get_if<I>(v);
|
|
}
|
|
|
|
template <std::size_t I, typename... Ts>
|
|
inline constexpr lib::add_pointer_t<const variant_alternative_t<I, variant<Ts...>>>
|
|
get_if(const variant<Ts...>* v) noexcept
|
|
{
|
|
return detail::generic_get_if<I>(v);
|
|
}
|
|
|
|
template <typename T, typename... Ts>
|
|
inline constexpr lib::add_pointer_t<T> get_if(variant<Ts...>* v) noexcept
|
|
{
|
|
return get_if<detail::find_index_checked<T, Ts...>::value>(v);
|
|
}
|
|
|
|
template <typename T, typename... Ts>
|
|
inline constexpr lib::add_pointer_t<const T> get_if(const variant<Ts...>* v) noexcept
|
|
{
|
|
return get_if<detail::find_index_checked<T, Ts...>::value>(v);
|
|
}
|
|
|
|
template <typename... Ts>
|
|
inline constexpr bool operator==(const variant<Ts...>& lhs, const variant<Ts...>& rhs)
|
|
{
|
|
using detail::visitation::variant;
|
|
using lib::equal_to;
|
|
#ifdef MPARK_CPP14_CONSTEXPR
|
|
if (lhs.index() != rhs.index())
|
|
return false;
|
|
if (lhs.valueless_by_exception())
|
|
return true;
|
|
return variant::visit_value_at(lhs.index(), equal_to{}, lhs, rhs);
|
|
#else
|
|
return lhs.index() == rhs.index() && (lhs.valueless_by_exception() ||
|
|
variant::visit_value_at(lhs.index(), equal_to{}, lhs, rhs));
|
|
#endif
|
|
}
|
|
|
|
template <typename... Ts>
|
|
inline constexpr bool operator!=(const variant<Ts...>& lhs, const variant<Ts...>& rhs)
|
|
{
|
|
using detail::visitation::variant;
|
|
using lib::not_equal_to;
|
|
#ifdef MPARK_CPP14_CONSTEXPR
|
|
if (lhs.index() != rhs.index())
|
|
return true;
|
|
if (lhs.valueless_by_exception())
|
|
return false;
|
|
return variant::visit_value_at(lhs.index(), not_equal_to{}, lhs, rhs);
|
|
#else
|
|
return lhs.index() != rhs.index() ||
|
|
(!lhs.valueless_by_exception() &&
|
|
variant::visit_value_at(lhs.index(), not_equal_to{}, lhs, rhs));
|
|
#endif
|
|
}
|
|
|
|
template <typename... Ts>
|
|
inline constexpr bool operator<(const variant<Ts...>& lhs, const variant<Ts...>& rhs)
|
|
{
|
|
using detail::visitation::variant;
|
|
using lib::less;
|
|
#ifdef MPARK_CPP14_CONSTEXPR
|
|
if (rhs.valueless_by_exception())
|
|
return false;
|
|
if (lhs.valueless_by_exception())
|
|
return true;
|
|
if (lhs.index() < rhs.index())
|
|
return true;
|
|
if (lhs.index() > rhs.index())
|
|
return false;
|
|
return variant::visit_value_at(lhs.index(), less{}, lhs, rhs);
|
|
#else
|
|
return !rhs.valueless_by_exception() &&
|
|
(lhs.valueless_by_exception() || lhs.index() < rhs.index() ||
|
|
(lhs.index() == rhs.index() && variant::visit_value_at(lhs.index(), less{}, lhs, rhs)));
|
|
#endif
|
|
}
|
|
|
|
template <typename... Ts>
|
|
inline constexpr bool operator>(const variant<Ts...>& lhs, const variant<Ts...>& rhs)
|
|
{
|
|
using detail::visitation::variant;
|
|
using lib::greater;
|
|
#ifdef MPARK_CPP14_CONSTEXPR
|
|
if (lhs.valueless_by_exception())
|
|
return false;
|
|
if (rhs.valueless_by_exception())
|
|
return true;
|
|
if (lhs.index() > rhs.index())
|
|
return true;
|
|
if (lhs.index() < rhs.index())
|
|
return false;
|
|
return variant::visit_value_at(lhs.index(), greater{}, lhs, rhs);
|
|
#else
|
|
return !lhs.valueless_by_exception() &&
|
|
(rhs.valueless_by_exception() || lhs.index() > rhs.index() ||
|
|
(lhs.index() == rhs.index() &&
|
|
variant::visit_value_at(lhs.index(), greater{}, lhs, rhs)));
|
|
#endif
|
|
}
|
|
|
|
template <typename... Ts>
|
|
inline constexpr bool operator<=(const variant<Ts...>& lhs, const variant<Ts...>& rhs)
|
|
{
|
|
using detail::visitation::variant;
|
|
using lib::less_equal;
|
|
#ifdef MPARK_CPP14_CONSTEXPR
|
|
if (lhs.valueless_by_exception())
|
|
return true;
|
|
if (rhs.valueless_by_exception())
|
|
return false;
|
|
if (lhs.index() < rhs.index())
|
|
return true;
|
|
if (lhs.index() > rhs.index())
|
|
return false;
|
|
return variant::visit_value_at(lhs.index(), less_equal{}, lhs, rhs);
|
|
#else
|
|
return lhs.valueless_by_exception() ||
|
|
(!rhs.valueless_by_exception() &&
|
|
(lhs.index() < rhs.index() ||
|
|
(lhs.index() == rhs.index() &&
|
|
variant::visit_value_at(lhs.index(), less_equal{}, lhs, rhs))));
|
|
#endif
|
|
}
|
|
|
|
template <typename... Ts>
|
|
inline constexpr bool operator>=(const variant<Ts...>& lhs, const variant<Ts...>& rhs)
|
|
{
|
|
using detail::visitation::variant;
|
|
using lib::greater_equal;
|
|
#ifdef MPARK_CPP14_CONSTEXPR
|
|
if (rhs.valueless_by_exception())
|
|
return true;
|
|
if (lhs.valueless_by_exception())
|
|
return false;
|
|
if (lhs.index() > rhs.index())
|
|
return true;
|
|
if (lhs.index() < rhs.index())
|
|
return false;
|
|
return variant::visit_value_at(lhs.index(), greater_equal{}, lhs, rhs);
|
|
#else
|
|
return rhs.valueless_by_exception() ||
|
|
(!lhs.valueless_by_exception() &&
|
|
(lhs.index() > rhs.index() ||
|
|
(lhs.index() == rhs.index() &&
|
|
variant::visit_value_at(lhs.index(), greater_equal{}, lhs, rhs))));
|
|
#endif
|
|
}
|
|
|
|
template <typename Visitor, typename... Vs>
|
|
inline constexpr DECLTYPE_AUTO visit(Visitor&& visitor, Vs&&... vs) DECLTYPE_AUTO_RETURN(
|
|
(detail::all(!vs.valueless_by_exception()...) ? (void)0 : throw_bad_variant_access()),
|
|
detail::visitation::variant::visit_value(lib::forward<Visitor>(visitor),
|
|
lib::forward<Vs>(vs)...))
|
|
|
|
struct monostate
|
|
{
|
|
};
|
|
|
|
inline constexpr bool operator<(monostate, monostate) noexcept
|
|
{
|
|
return false;
|
|
}
|
|
|
|
inline constexpr bool operator>(monostate, monostate) noexcept
|
|
{
|
|
return false;
|
|
}
|
|
|
|
inline constexpr bool operator<=(monostate, monostate) noexcept
|
|
{
|
|
return true;
|
|
}
|
|
|
|
inline constexpr bool operator>=(monostate, monostate) noexcept
|
|
{
|
|
return true;
|
|
}
|
|
|
|
inline constexpr bool operator==(monostate, monostate) noexcept
|
|
{
|
|
return true;
|
|
}
|
|
|
|
inline constexpr bool operator!=(monostate, monostate) noexcept
|
|
{
|
|
return false;
|
|
}
|
|
|
|
template <typename... Ts>
|
|
inline auto swap(variant<Ts...>& lhs, variant<Ts...>& rhs) noexcept(noexcept(lhs.swap(rhs)))
|
|
-> decltype(lhs.swap(rhs))
|
|
{
|
|
lhs.swap(rhs);
|
|
}
|
|
|
|
namespace detail
|
|
{
|
|
template <typename T, typename...>
|
|
using enabled_type = T;
|
|
|
|
namespace hash
|
|
{
|
|
template <typename H, typename K>
|
|
constexpr bool meets_requirements()
|
|
{
|
|
return std::is_copy_constructible<H>::value && std::is_move_constructible<H>::value &&
|
|
lib::is_invocable_r<std::size_t, H, const K&>::value;
|
|
}
|
|
|
|
template <typename K>
|
|
constexpr bool is_enabled()
|
|
{
|
|
using H = std::hash<K>;
|
|
return meets_requirements<H, K>() && std::is_default_constructible<H>::value &&
|
|
std::is_copy_assignable<H>::value && std::is_move_assignable<H>::value;
|
|
}
|
|
|
|
} // namespace hash
|
|
|
|
} // namespace detail
|
|
|
|
#undef AUTO
|
|
#undef AUTO_RETURN
|
|
|
|
#undef AUTO_REFREF
|
|
#undef AUTO_REFREF_RETURN
|
|
|
|
#undef DECLTYPE_AUTO
|
|
#undef DECLTYPE_AUTO_RETURN
|
|
|
|
} // namespace mpark
|
|
|
|
namespace std
|
|
{
|
|
template <typename... Ts>
|
|
struct hash<mpark::detail::enabled_type<
|
|
mpark::variant<Ts...>, mpark::lib::enable_if_t<mpark::lib::all<mpark::detail::hash::is_enabled<
|
|
mpark::lib::remove_const_t<Ts>>()...>::value>>>
|
|
{
|
|
using argument_type = mpark::variant<Ts...>;
|
|
using result_type = std::size_t;
|
|
|
|
inline result_type operator()(const argument_type& v) const
|
|
{
|
|
using mpark::detail::visitation::variant;
|
|
std::size_t result = v.valueless_by_exception() ?
|
|
299792458 // Random value chosen by the universe upon creation
|
|
:
|
|
variant::visit_alt(
|
|
#ifdef MPARK_GENERIC_LAMBDAS
|
|
[](const auto& alt) {
|
|
using alt_type = mpark::lib::decay_t<decltype(alt)>;
|
|
using value_type =
|
|
mpark::lib::remove_const_t<typename alt_type::value_type>;
|
|
return hash<value_type>{}(alt.value);
|
|
}
|
|
#else
|
|
hasher {}
|
|
#endif
|
|
,
|
|
v);
|
|
return hash_combine(result, hash<std::size_t>{}(v.index()));
|
|
}
|
|
|
|
private:
|
|
#ifndef MPARK_GENERIC_LAMBDAS
|
|
struct hasher
|
|
{
|
|
template <typename Alt>
|
|
inline std::size_t operator()(const Alt& alt) const
|
|
{
|
|
using alt_type = mpark::lib::decay_t<Alt>;
|
|
using value_type = mpark::lib::remove_const_t<typename alt_type::value_type>;
|
|
return hash<value_type>{}(alt.value);
|
|
}
|
|
};
|
|
#endif
|
|
|
|
static std::size_t hash_combine(std::size_t lhs, std::size_t rhs)
|
|
{
|
|
return lhs ^= rhs + 0x9e3779b9 + (lhs << 6) + (lhs >> 2);
|
|
}
|
|
};
|
|
|
|
template <>
|
|
struct hash<mpark::monostate>
|
|
{
|
|
using argument_type = mpark::monostate;
|
|
using result_type = std::size_t;
|
|
|
|
inline result_type operator()(const argument_type&) const noexcept
|
|
{
|
|
return 66740831; // return a fundamentally attractive random value.
|
|
}
|
|
};
|
|
|
|
} // namespace std
|
|
|
|
namespace std
|
|
{
|
|
using mpark::variant;
|
|
using mpark::visit;
|
|
using mpark::holds_alternative;
|
|
using mpark::get;
|
|
using mpark::get_if;
|
|
using mpark::monostate;
|
|
using mpark::bad_variant_access;
|
|
using mpark::variant_size;
|
|
using mpark::variant_alternative;
|
|
using mpark::variant_alternative_t;
|
|
} // namespace std
|
|
#endif
|