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538 lines
17 KiB
538 lines
17 KiB
// 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 <memory>
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#include <functional>
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#include <type_traits>
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#include <utility>
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#include "config.hpp"
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#define MPARK_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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namespace lib {
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template <typename T>
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struct identity { using type = T; };
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inline namespace cpp14 {
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template <typename T, std::size_t N>
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struct array {
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constexpr const T &operator[](std::size_t index) const {
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return data[index];
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}
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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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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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static_assert(!std::is_lvalue_reference<T>::value,
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"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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inline constexpr remove_reference_t<T> &&move(T &&t) noexcept {
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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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using std::integer_sequence;
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using std::index_sequence;
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using std::make_index_sequence;
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using std::index_sequence_for;
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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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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...>,
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index_sequence<Rhs...>>
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: identity<index_sequence<Lhs..., (sizeof...(Lhs) + Rhs)...>> {};
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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>,
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make_index_sequence<N - (N / 2)>> {};
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template <>
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struct make_index_sequence_impl<0> : identity<index_sequence<>> {};
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template <>
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struct make_index_sequence_impl<1> : identity<index_sequence<0>> {};
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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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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs &&lhs, Rhs &&rhs) const
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MPARK_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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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs &&lhs, Rhs &&rhs) const
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MPARK_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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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs &&lhs, Rhs &&rhs) const
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MPARK_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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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs &&lhs, Rhs &&rhs) const
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MPARK_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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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs &&lhs, Rhs &&rhs) const
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MPARK_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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template <typename Lhs, typename Rhs>
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inline constexpr auto operator()(Lhs &&lhs, Rhs &&rhs) const
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MPARK_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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// <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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struct voider : identity<void> {};
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template <typename... Ts>
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using void_t = typename voider<Ts...>::type;
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namespace detail {
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namespace swappable {
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using std::swap;
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template <typename T>
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struct is_swappable {
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private:
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template <typename U,
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typename = decltype(swap(std::declval<U &>(),
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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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static constexpr bool value = decltype(test<T>(0))::value;
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};
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template <bool IsSwappable, typename T>
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struct is_nothrow_swappable {
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static constexpr bool value =
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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<false, T> : std::false_type {};
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} // namespace swappable
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} // namespace detail
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using detail::swappable::is_swappable;
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template <typename T>
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using is_nothrow_swappable =
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detail::swappable::is_nothrow_swappable<is_swappable<T>::value, T>;
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// <functional>
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namespace detail {
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template <typename T>
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struct is_reference_wrapper : std::false_type {};
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template <typename T>
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struct is_reference_wrapper<std::reference_wrapper<T>>
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: std::true_type {};
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template <bool, int>
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struct Invoke;
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template <>
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struct Invoke<true /* pmf */, 0 /* is_base_of */> {
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template <typename R, typename T, typename Arg, typename... Args>
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inline static constexpr auto invoke(R T::*pmf, Arg &&arg, Args &&... args)
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MPARK_RETURN((lib::forward<Arg>(arg).*pmf)(lib::forward<Args>(args)...))
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};
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template <>
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struct Invoke<true /* pmf */, 1 /* is_reference_wrapper */> {
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template <typename R, typename T, typename Arg, typename... Args>
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inline static constexpr auto invoke(R T::*pmf, Arg &&arg, Args &&... args)
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MPARK_RETURN((lib::forward<Arg>(arg).get().*pmf)(lib::forward<Args>(args)...))
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};
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template <>
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struct Invoke<true /* pmf */, 2 /* otherwise */> {
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template <typename R, typename T, typename Arg, typename... Args>
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inline static constexpr auto invoke(R T::*pmf, Arg &&arg, Args &&... args)
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MPARK_RETURN(((*lib::forward<Arg>(arg)).*pmf)(lib::forward<Args>(args)...))
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};
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template <>
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struct Invoke<false /* pmo */, 0 /* is_base_of */> {
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template <typename R, typename T, typename Arg>
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inline static constexpr auto invoke(R T::*pmo, Arg &&arg)
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MPARK_RETURN(lib::forward<Arg>(arg).*pmo)
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};
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template <>
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struct Invoke<false /* pmo */, 1 /* is_reference_wrapper */> {
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template <typename R, typename T, typename Arg>
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inline static constexpr auto invoke(R T::*pmo, Arg &&arg)
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MPARK_RETURN(lib::forward<Arg>(arg).get().*pmo)
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};
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template <>
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struct Invoke<false /* pmo */, 2 /* otherwise */> {
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template <typename R, typename T, typename Arg>
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inline static constexpr auto invoke(R T::*pmo, Arg &&arg)
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MPARK_RETURN((*lib::forward<Arg>(arg)).*pmo)
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};
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template <typename R, typename T, typename Arg, typename... Args>
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inline constexpr auto invoke(R T::*f, Arg &&arg, Args &&... args)
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MPARK_RETURN(
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Invoke<std::is_function<R>::value,
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(std::is_base_of<T, lib::decay_t<Arg>>::value
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? 0
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: is_reference_wrapper<lib::decay_t<Arg>>::value
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? 1
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: 2)>::invoke(f,
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lib::forward<Arg>(arg),
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lib::forward<Args>(args)...))
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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... Args>
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inline constexpr auto invoke(F &&f, Args &&... args)
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MPARK_RETURN(lib::forward<F>(f)(lib::forward<Args>(args)...))
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#ifdef _MSC_VER
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#pragma warning(pop)
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#endif
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} // namespace detail
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template <typename F, typename... Args>
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inline constexpr auto invoke(F &&f, Args &&... args)
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MPARK_RETURN(detail::invoke(lib::forward<F>(f),
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lib::forward<Args>(args)...))
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namespace detail {
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template <typename Void, typename, typename...>
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struct invoke_result {};
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template <typename F, typename... Args>
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struct invoke_result<void_t<decltype(lib::invoke(
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std::declval<F>(), std::declval<Args>()...))>,
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F,
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Args...>
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: identity<decltype(
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lib::invoke(std::declval<F>(), std::declval<Args>()...))> {};
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} // namespace detail
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template <typename F, typename... Args>
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using invoke_result = detail::invoke_result<void, F, Args...>;
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template <typename F, typename... Args>
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using invoke_result_t = typename invoke_result<F, Args...>::type;
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namespace detail {
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template <typename Void, typename, typename...>
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struct is_invocable : std::false_type {};
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template <typename F, typename... Args>
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struct is_invocable<void_t<invoke_result_t<F, Args...>>, F, Args...>
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: std::true_type {};
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template <typename Void, typename, typename, typename...>
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struct is_invocable_r : std::false_type {};
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template <typename R, typename F, typename... Args>
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struct is_invocable_r<void_t<invoke_result_t<F, Args...>>,
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R,
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F,
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Args...>
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: std::is_convertible<invoke_result_t<F, Args...>, R> {};
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} // namespace detail
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template <typename F, typename... Args>
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using is_invocable = detail::is_invocable<void, F, Args...>;
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template <typename R, typename F, typename... Args>
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using is_invocable_r = detail::is_invocable_r<void, R, F, Args...>;
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namespace detail {
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template <bool Invocable, typename F, typename... Args>
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struct is_nothrow_invocable {
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static constexpr bool value =
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noexcept(lib::invoke(std::declval<F>(), std::declval<Args>()...));
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};
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template <typename F, typename... Args>
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struct is_nothrow_invocable<false, F, Args...> : std::false_type {};
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template <bool Invocable, typename R, typename F, typename... Args>
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struct is_nothrow_invocable_r {
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private:
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inline static R impl() {
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return lib::invoke(std::declval<F>(), std::declval<Args>()...);
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}
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public:
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static constexpr bool value = noexcept(impl());
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};
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template <typename R, typename F, typename... Args>
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struct is_nothrow_invocable_r<false, R, F, Args...> : std::false_type {};
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} // namespace detail
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template <typename F, typename... Args>
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using is_nothrow_invocable = detail::
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is_nothrow_invocable<is_invocable<F, Args...>::value, F, Args...>;
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template <typename R, typename F, typename... Args>
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using is_nothrow_invocable_r =
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detail::is_nothrow_invocable_r<is_invocable_r<R, F, Args...>::value,
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R,
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F,
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Args...>;
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// <memory>
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#ifdef MPARK_BUILTIN_ADDRESSOF
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template <typename T>
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inline constexpr T *addressof(T &arg) noexcept {
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return __builtin_addressof(arg);
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}
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#else
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namespace detail {
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namespace has_addressof_impl {
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struct fail;
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template <typename T>
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inline fail operator&(T &&);
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template <typename T>
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inline static constexpr bool impl() {
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return (std::is_class<T>::value || std::is_union<T>::value) &&
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!std::is_same<decltype(&std::declval<T &>()), fail>::value;
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}
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} // namespace has_addressof_impl
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template <typename T>
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using has_addressof = bool_constant<has_addressof_impl::impl<T>()>;
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template <typename T>
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inline constexpr T *addressof(T &arg, std::true_type) noexcept {
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return std::addressof(arg);
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}
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template <typename T>
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inline constexpr T *addressof(T &arg, std::false_type) noexcept {
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return &arg;
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}
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} // namespace detail
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template <typename T>
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inline constexpr T *addressof(T &arg) noexcept {
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return detail::addressof(arg, detail::has_addressof<T>{});
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}
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#endif
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template <typename T>
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inline constexpr T *addressof(const T &&) = delete;
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} // namespace cpp17
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template <typename T>
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struct remove_all_extents : identity<T> {};
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template <typename T, std::size_t N>
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struct remove_all_extents<array<T, N>> : remove_all_extents<T> {};
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template <typename T>
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using remove_all_extents_t = typename remove_all_extents<T>::type;
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template <std::size_t N>
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using size_constant = std::integral_constant<std::size_t, N>;
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template <std::size_t I, typename T>
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struct indexed_type : size_constant<I> { using type = T; };
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template <bool... Bs>
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using all = std::is_same<integer_sequence<bool, true, Bs...>,
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integer_sequence<bool, Bs..., true>>;
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#ifdef MPARK_TYPE_PACK_ELEMENT
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template <std::size_t I, typename... Ts>
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using type_pack_element_t = __type_pack_element<I, Ts...>;
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#else
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template <std::size_t I, typename... Ts>
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struct type_pack_element_impl {
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private:
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template <typename>
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struct set;
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template <std::size_t... Is>
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struct set<index_sequence<Is...>> : indexed_type<Is, Ts>... {};
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template <typename T>
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inline static std::enable_if<true, T> impl(indexed_type<I, T>);
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inline static std::enable_if<false> impl(...);
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public:
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using type = decltype(impl(set<index_sequence_for<Ts...>>{}));
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};
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template <std::size_t I, typename... Ts>
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using type_pack_element = typename type_pack_element_impl<I, Ts...>::type;
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template <std::size_t I, typename... Ts>
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using type_pack_element_t = typename type_pack_element<I, Ts...>::type;
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#endif
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#ifdef MPARK_TRIVIALITY_TYPE_TRAITS
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using std::is_trivially_copy_constructible;
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using std::is_trivially_move_constructible;
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using std::is_trivially_copy_assignable;
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using std::is_trivially_move_assignable;
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#else
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template <typename T>
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struct is_trivially_copy_constructible
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: bool_constant<
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std::is_copy_constructible<T>::value && __has_trivial_copy(T)> {};
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template <typename T>
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struct is_trivially_move_constructible : bool_constant<__is_trivial(T)> {};
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template <typename T>
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struct is_trivially_copy_assignable
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: bool_constant<
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std::is_copy_assignable<T>::value && __has_trivial_assign(T)> {};
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template <typename T>
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struct is_trivially_move_assignable : bool_constant<__is_trivial(T)> {};
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#endif
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template <typename T, bool>
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struct dependent_type : T {};
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template <typename Is, std::size_t J>
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struct push_back;
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template <typename Is, std::size_t J>
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using push_back_t = typename push_back<Is, J>::type;
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template <std::size_t... Is, std::size_t J>
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struct push_back<index_sequence<Is...>, J> {
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using type = index_sequence<Is..., J>;
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};
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} // namespace lib
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} // namespace mpark
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#undef MPARK_RETURN
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#endif // MPARK_LIB_HPP
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