mirror of
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1040 lines
28 KiB
C++
1040 lines
28 KiB
C++
// Copyright (C) 2011 - 2012 Andrzej Krzemienski.
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//
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// Use, modification, and distribution is subject to the Boost Software
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// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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// The idea and interface is based on Boost.Optional library
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// authored by Fernando Luis Cacciola Carballal
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# ifndef ___OPTIONAL_HPP___
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# define ___OPTIONAL_HPP___
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# include <utility>
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# include <type_traits>
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# include <initializer_list>
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# include <cassert>
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# include <functional>
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# include <string>
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# include <stdexcept>
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# define TR2_OPTIONAL_REQUIRES(...) typename enable_if<__VA_ARGS__::value, bool>::type = false
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# if defined __GNUC__ // NOTE: GNUC is also defined for Clang
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# if (__GNUC__ == 4) && (__GNUC_MINOR__ >= 8)
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# define TR2_OPTIONAL_GCC_4_8_AND_HIGHER___
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# elif (__GNUC__ > 4)
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# define TR2_OPTIONAL_GCC_4_8_AND_HIGHER___
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# endif
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#
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# if (__GNUC__ == 4) && (__GNUC_MINOR__ >= 7)
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# define TR2_OPTIONAL_GCC_4_7_AND_HIGHER___
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# elif (__GNUC__ > 4)
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# define TR2_OPTIONAL_GCC_4_7_AND_HIGHER___
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# endif
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#
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# if (__GNUC__ == 4) && (__GNUC_MINOR__ == 8) && (__GNUC_PATCHLEVEL__ >= 1)
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# define TR2_OPTIONAL_GCC_4_8_1_AND_HIGHER___
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# elif (__GNUC__ == 4) && (__GNUC_MINOR__ >= 9)
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# define TR2_OPTIONAL_GCC_4_8_1_AND_HIGHER___
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# elif (__GNUC__ > 4)
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# define TR2_OPTIONAL_GCC_4_8_1_AND_HIGHER___
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# endif
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# endif
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#
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# if defined __clang_major__
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# if (__clang_major__ == 3 && __clang_minor__ >= 5)
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# define TR2_OPTIONAL_CLANG_3_5_AND_HIGHTER_
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# elif (__clang_major__ > 3)
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# define TR2_OPTIONAL_CLANG_3_5_AND_HIGHTER_
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# endif
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# if defined TR2_OPTIONAL_CLANG_3_5_AND_HIGHTER_
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# define TR2_OPTIONAL_CLANG_3_4_2_AND_HIGHER_
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# elif (__clang_major__ == 3 && __clang_minor__ == 4 && __clang_patchlevel__ >= 2)
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# define TR2_OPTIONAL_CLANG_3_4_2_AND_HIGHER_
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# endif
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# endif
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#
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# if defined _MSC_VER
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# if (_MSC_VER >= 1900)
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# define TR2_OPTIONAL_MSVC_2015_AND_HIGHER___
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# endif
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# endif
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# if defined __clang__
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# if (__clang_major__ > 2) || (__clang_major__ == 2) && (__clang_minor__ >= 9)
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# define OPTIONAL_HAS_THIS_RVALUE_REFS 1
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# else
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# define OPTIONAL_HAS_THIS_RVALUE_REFS 0
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# endif
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# elif defined TR2_OPTIONAL_GCC_4_8_1_AND_HIGHER___
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# define OPTIONAL_HAS_THIS_RVALUE_REFS 1
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# elif defined TR2_OPTIONAL_MSVC_2015_AND_HIGHER___
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# define OPTIONAL_HAS_THIS_RVALUE_REFS 1
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# else
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# define OPTIONAL_HAS_THIS_RVALUE_REFS 0
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# endif
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# if defined TR2_OPTIONAL_GCC_4_8_1_AND_HIGHER___
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# define OPTIONAL_HAS_CONSTEXPR_INIT_LIST 1
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# define OPTIONAL_CONSTEXPR_INIT_LIST constexpr
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# else
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# define OPTIONAL_HAS_CONSTEXPR_INIT_LIST 0
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# define OPTIONAL_CONSTEXPR_INIT_LIST
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# endif
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# if defined TR2_OPTIONAL_CLANG_3_5_AND_HIGHTER_ && (defined __cplusplus) && (__cplusplus != 201103L)
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# define OPTIONAL_HAS_MOVE_ACCESSORS 1
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# else
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# define OPTIONAL_HAS_MOVE_ACCESSORS 0
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# endif
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# // In C++11 constexpr implies const, so we need to make non-const members also non-constexpr
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# if (defined __cplusplus) && (__cplusplus == 201103L)
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# define OPTIONAL_MUTABLE_CONSTEXPR
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# else
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# define OPTIONAL_MUTABLE_CONSTEXPR constexpr
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# endif
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namespace std{
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// BEGIN workaround for missing is_trivially_destructible
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# if defined TR2_OPTIONAL_GCC_4_8_AND_HIGHER___
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// leave it: it is already there
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# elif defined TR2_OPTIONAL_CLANG_3_4_2_AND_HIGHER_
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// leave it: it is already there
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# elif defined TR2_OPTIONAL_MSVC_2015_AND_HIGHER___
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// leave it: it is already there
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# elif defined TR2_OPTIONAL_DISABLE_EMULATION_OF_TYPE_TRAITS
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// leave it: the user doesn't want it
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# else
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template <typename T>
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using is_trivially_destructible = std::has_trivial_destructor<T>;
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# endif
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// END workaround for missing is_trivially_destructible
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# if (defined TR2_OPTIONAL_GCC_4_7_AND_HIGHER___)
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// leave it; our metafunctions are already defined.
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# elif defined TR2_OPTIONAL_CLANG_3_4_2_AND_HIGHER_
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// leave it; our metafunctions are already defined.
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# elif defined TR2_OPTIONAL_MSVC_2015_AND_HIGHER___
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// leave it: it is already there
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# elif defined TR2_OPTIONAL_DISABLE_EMULATION_OF_TYPE_TRAITS
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// leave it: the user doesn't want it
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# else
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// workaround for missing traits in GCC and CLANG
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template <class T>
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struct is_nothrow_move_constructible
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{
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constexpr static bool value = std::is_nothrow_constructible<T, T&&>::value;
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};
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template <class T, class U>
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struct is_assignable
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{
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template <class X, class Y>
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constexpr static bool has_assign(...) { return false; }
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template <class X, class Y, size_t S = sizeof((std::declval<X>() = std::declval<Y>(), true)) >
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// the comma operator is necessary for the cases where operator= returns void
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constexpr static bool has_assign(bool) { return true; }
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constexpr static bool value = has_assign<T, U>(true);
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};
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template <class T>
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struct is_nothrow_move_assignable
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{
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template <class X, bool has_any_move_assign>
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struct has_nothrow_move_assign {
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constexpr static bool value = false;
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};
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template <class X>
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struct has_nothrow_move_assign<X, true> {
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constexpr static bool value = noexcept( std::declval<X&>() = std::declval<X&&>() );
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};
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constexpr static bool value = has_nothrow_move_assign<T, is_assignable<T&, T&&>::value>::value;
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};
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// end workaround
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# endif
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// 20.5.4, optional for object types
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template <class T> class optional;
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// 20.5.5, optional for lvalue reference types
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template <class T> class optional<T&>;
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// workaround: std utility functions aren't constexpr yet
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template <class T> inline constexpr T&& constexpr_forward(typename std::remove_reference<T>::type& t) noexcept
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{
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return static_cast<T&&>(t);
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}
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template <class T> inline constexpr T&& constexpr_forward(typename std::remove_reference<T>::type&& t) noexcept
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{
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static_assert(!std::is_lvalue_reference<T>::value, "!!");
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return static_cast<T&&>(t);
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}
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template <class T> inline constexpr typename std::remove_reference<T>::type&& constexpr_move(T&& t) noexcept
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{
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return static_cast<typename std::remove_reference<T>::type&&>(t);
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}
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#if defined NDEBUG
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# define TR2_OPTIONAL_ASSERTED_EXPRESSION(CHECK, EXPR) (EXPR)
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#else
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# define TR2_OPTIONAL_ASSERTED_EXPRESSION(CHECK, EXPR) ((CHECK) ? (EXPR) : ([]{assert(!#CHECK);}(), (EXPR)))
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#endif
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namespace detail_
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{
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// static_addressof: a constexpr version of addressof
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template <typename T>
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struct has_overloaded_addressof
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{
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template <class X>
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constexpr static bool has_overload(...) { return false; }
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template <class X, size_t S = sizeof(std::declval<X&>().operator&()) >
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constexpr static bool has_overload(bool) { return true; }
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constexpr static bool value = has_overload<T>(true);
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};
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template <typename T, TR2_OPTIONAL_REQUIRES(!has_overloaded_addressof<T>)>
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constexpr T* static_addressof(T& ref)
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{
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return &ref;
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}
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template <typename T, TR2_OPTIONAL_REQUIRES(has_overloaded_addressof<T>)>
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T* static_addressof(T& ref)
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{
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return std::addressof(ref);
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}
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// the call to convert<A>(b) has return type A and converts b to type A iff b decltype(b) is implicitly convertible to A
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template <class U>
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constexpr U convert(U v) { return v; }
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} // namespace detail
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constexpr struct trivial_init_t{} trivial_init{};
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// 20.5.6, In-place construction
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constexpr struct in_place_t{} in_place{};
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// 20.5.7, Disengaged state indicator
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struct nullopt_t
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{
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struct init{};
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constexpr explicit nullopt_t(init){}
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};
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constexpr nullopt_t nullopt{nullopt_t::init()};
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// 20.5.8, class bad_optional_access
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class bad_optional_access : public logic_error {
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public:
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explicit bad_optional_access(const string& what_arg) : logic_error{what_arg} {}
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explicit bad_optional_access(const char* what_arg) : logic_error{what_arg} {}
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};
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template <class T>
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union storage_t
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{
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unsigned char dummy_;
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T value_;
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constexpr storage_t( trivial_init_t ) noexcept : dummy_() {};
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template <class... Args>
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constexpr storage_t( Args&&... args ) : value_(constexpr_forward<Args>(args)...) {}
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~storage_t(){}
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};
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template <class T>
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union constexpr_storage_t
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{
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unsigned char dummy_;
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T value_;
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constexpr constexpr_storage_t( trivial_init_t ) noexcept : dummy_() {};
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template <class... Args>
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constexpr constexpr_storage_t( Args&&... args ) : value_(constexpr_forward<Args>(args)...) {}
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~constexpr_storage_t() = default;
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};
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template <class T>
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struct optional_base
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{
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bool init_;
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storage_t<T> storage_;
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constexpr optional_base() noexcept : init_(false), storage_(trivial_init) {};
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explicit constexpr optional_base(const T& v) : init_(true), storage_(v) {}
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explicit constexpr optional_base(T&& v) : init_(true), storage_(constexpr_move(v)) {}
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template <class... Args> explicit optional_base(in_place_t, Args&&... args)
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: init_(true), storage_(constexpr_forward<Args>(args)...) {}
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template <class U, class... Args, TR2_OPTIONAL_REQUIRES(is_constructible<T, std::initializer_list<U>>)>
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explicit optional_base(in_place_t, std::initializer_list<U> il, Args&&... args)
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: init_(true), storage_(il, std::forward<Args>(args)...) {}
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~optional_base() { if (init_) storage_.value_.T::~T(); }
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};
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template <class T>
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struct constexpr_optional_base
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{
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bool init_;
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constexpr_storage_t<T> storage_;
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constexpr constexpr_optional_base() noexcept : init_(false), storage_(trivial_init) {};
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explicit constexpr constexpr_optional_base(const T& v) : init_(true), storage_(v) {}
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explicit constexpr constexpr_optional_base(T&& v) : init_(true), storage_(constexpr_move(v)) {}
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template <class... Args> explicit constexpr constexpr_optional_base(in_place_t, Args&&... args)
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: init_(true), storage_(constexpr_forward<Args>(args)...) {}
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template <class U, class... Args, TR2_OPTIONAL_REQUIRES(is_constructible<T, std::initializer_list<U>>)>
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OPTIONAL_CONSTEXPR_INIT_LIST explicit constexpr_optional_base(in_place_t, std::initializer_list<U> il, Args&&... args)
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: init_(true), storage_(il, std::forward<Args>(args)...) {}
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~constexpr_optional_base() = default;
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};
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template <class T>
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using OptionalBase = typename std::conditional<
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is_trivially_destructible<T>::value,
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constexpr_optional_base<typename std::remove_const<T>::type>,
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optional_base<typename std::remove_const<T>::type>
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>::type;
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template <class T>
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class optional : private OptionalBase<T>
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{
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static_assert( !std::is_same<typename std::decay<T>::type, nullopt_t>::value, "bad T" );
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static_assert( !std::is_same<typename std::decay<T>::type, in_place_t>::value, "bad T" );
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constexpr bool initialized() const noexcept { return OptionalBase<T>::init_; }
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typename std::remove_const<T>::type* dataptr() { return std::addressof(OptionalBase<T>::storage_.value_); }
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constexpr const T* dataptr() const { return detail_::static_addressof(OptionalBase<T>::storage_.value_); }
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# if OPTIONAL_HAS_THIS_RVALUE_REFS == 1
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constexpr const T& contained_val() const& { return OptionalBase<T>::storage_.value_; }
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# if OPTIONAL_HAS_MOVE_ACCESSORS == 1
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OPTIONAL_MUTABLE_CONSTEXPR T&& contained_val() && { return std::move(OptionalBase<T>::storage_.value_); }
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OPTIONAL_MUTABLE_CONSTEXPR T& contained_val() & { return OptionalBase<T>::storage_.value_; }
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# else
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T& contained_val() & { return OptionalBase<T>::storage_.value_; }
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T&& contained_val() && { return std::move(OptionalBase<T>::storage_.value_); }
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# endif
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# else
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constexpr const T& contained_val() const { return OptionalBase<T>::storage_.value_; }
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T& contained_val() { return OptionalBase<T>::storage_.value_; }
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# endif
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void clear() noexcept {
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if (initialized()) dataptr()->T::~T();
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OptionalBase<T>::init_ = false;
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}
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template <class... Args>
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void initialize(Args&&... args) noexcept(noexcept(T(std::forward<Args>(args)...)))
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{
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assert(!OptionalBase<T>::init_);
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::new (static_cast<void*>(dataptr())) T(std::forward<Args>(args)...);
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OptionalBase<T>::init_ = true;
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}
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template <class U, class... Args>
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void initialize(std::initializer_list<U> il, Args&&... args) noexcept(noexcept(T(il, std::forward<Args>(args)...)))
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{
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assert(!OptionalBase<T>::init_);
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::new (static_cast<void*>(dataptr())) T(il, std::forward<Args>(args)...);
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OptionalBase<T>::init_ = true;
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}
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public:
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typedef T value_type;
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// 20.5.5.1, constructors
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constexpr optional() noexcept : OptionalBase<T>() {};
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constexpr optional(nullopt_t) noexcept : OptionalBase<T>() {};
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optional(const optional& rhs)
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: OptionalBase<T>()
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{
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if (rhs.initialized()) {
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::new (static_cast<void*>(dataptr())) T(*rhs);
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OptionalBase<T>::init_ = true;
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}
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}
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optional(optional&& rhs) noexcept(is_nothrow_move_constructible<T>::value)
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: OptionalBase<T>()
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{
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if (rhs.initialized()) {
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::new (static_cast<void*>(dataptr())) T(std::move(*rhs));
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OptionalBase<T>::init_ = true;
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}
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}
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constexpr optional(const T& v) : OptionalBase<T>(v) {}
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constexpr optional(T&& v) : OptionalBase<T>(constexpr_move(v)) {}
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template <class... Args>
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explicit constexpr optional(in_place_t, Args&&... args)
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: OptionalBase<T>(in_place_t{}, constexpr_forward<Args>(args)...) {}
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template <class U, class... Args, TR2_OPTIONAL_REQUIRES(is_constructible<T, std::initializer_list<U>>)>
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OPTIONAL_CONSTEXPR_INIT_LIST explicit optional(in_place_t, std::initializer_list<U> il, Args&&... args)
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: OptionalBase<T>(in_place_t{}, il, constexpr_forward<Args>(args)...) {}
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// 20.5.4.2, Destructor
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~optional() = default;
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// 20.5.4.3, assignment
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optional& operator=(nullopt_t) noexcept
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{
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clear();
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return *this;
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}
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optional& operator=(const optional& rhs)
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{
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if (initialized() == true && rhs.initialized() == false) clear();
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else if (initialized() == false && rhs.initialized() == true) initialize(*rhs);
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else if (initialized() == true && rhs.initialized() == true) contained_val() = *rhs;
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return *this;
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}
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optional& operator=(optional&& rhs)
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noexcept(is_nothrow_move_assignable<T>::value && is_nothrow_move_constructible<T>::value)
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{
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if (initialized() == true && rhs.initialized() == false) clear();
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else if (initialized() == false && rhs.initialized() == true) initialize(std::move(*rhs));
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else if (initialized() == true && rhs.initialized() == true) contained_val() = std::move(*rhs);
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return *this;
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}
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template <class U>
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auto operator=(U&& v)
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-> typename enable_if
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<
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is_same<typename decay<U>::type, T>::value,
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optional&
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>::type
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{
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if (initialized()) { contained_val() = std::forward<U>(v); }
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else { initialize(std::forward<U>(v)); }
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return *this;
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}
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template <class... Args>
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void emplace(Args&&... args)
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{
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clear();
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initialize(std::forward<Args>(args)...);
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}
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template <class U, class... Args>
|
|
void emplace(initializer_list<U> il, Args&&... args)
|
|
{
|
|
clear();
|
|
initialize<U, Args...>(il, std::forward<Args>(args)...);
|
|
}
|
|
|
|
// 20.5.4.4, Swap
|
|
void swap(optional<T>& rhs) noexcept(is_nothrow_move_constructible<T>::value && noexcept(swap(declval<T&>(), declval<T&>())))
|
|
{
|
|
if (initialized() == true && rhs.initialized() == false) { rhs.initialize(std::move(**this)); clear(); }
|
|
else if (initialized() == false && rhs.initialized() == true) { initialize(std::move(*rhs)); rhs.clear(); }
|
|
else if (initialized() == true && rhs.initialized() == true) { using std::swap; swap(**this, *rhs); }
|
|
}
|
|
|
|
// 20.5.4.5, Observers
|
|
|
|
explicit constexpr operator bool() const noexcept { return initialized(); }
|
|
|
|
constexpr T const* operator ->() const {
|
|
return TR2_OPTIONAL_ASSERTED_EXPRESSION(initialized(), dataptr());
|
|
}
|
|
|
|
# if OPTIONAL_HAS_MOVE_ACCESSORS == 1
|
|
|
|
OPTIONAL_MUTABLE_CONSTEXPR T* operator ->() {
|
|
assert (initialized());
|
|
return dataptr();
|
|
}
|
|
|
|
constexpr T const& operator *() const& {
|
|
return TR2_OPTIONAL_ASSERTED_EXPRESSION(initialized(), contained_val());
|
|
}
|
|
|
|
OPTIONAL_MUTABLE_CONSTEXPR T& operator *() & {
|
|
assert (initialized());
|
|
return contained_val();
|
|
}
|
|
|
|
OPTIONAL_MUTABLE_CONSTEXPR T&& operator *() && {
|
|
assert (initialized());
|
|
return constexpr_move(contained_val());
|
|
}
|
|
|
|
constexpr T const& value() const& {
|
|
return initialized() ? contained_val() : (throw bad_optional_access("bad optional access"), contained_val());
|
|
}
|
|
|
|
OPTIONAL_MUTABLE_CONSTEXPR T& value() & {
|
|
return initialized() ? contained_val() : (throw bad_optional_access("bad optional access"), contained_val());
|
|
}
|
|
|
|
OPTIONAL_MUTABLE_CONSTEXPR T&& value() && {
|
|
if (!initialized()) throw bad_optional_access("bad optional access");
|
|
return std::move(contained_val());
|
|
}
|
|
|
|
# else
|
|
|
|
T* operator ->() {
|
|
assert (initialized());
|
|
return dataptr();
|
|
}
|
|
|
|
constexpr T const& operator *() const {
|
|
return TR2_OPTIONAL_ASSERTED_EXPRESSION(initialized(), contained_val());
|
|
}
|
|
|
|
T& operator *() {
|
|
assert (initialized());
|
|
return contained_val();
|
|
}
|
|
|
|
constexpr T const& value() const {
|
|
return initialized() ? contained_val() : (throw bad_optional_access("bad optional access"), contained_val());
|
|
}
|
|
|
|
T& value() {
|
|
return initialized() ? contained_val() : (throw bad_optional_access("bad optional access"), contained_val());
|
|
}
|
|
|
|
# endif
|
|
|
|
# if OPTIONAL_HAS_THIS_RVALUE_REFS == 1
|
|
|
|
template <class V>
|
|
constexpr T value_or(V&& v) const&
|
|
{
|
|
return *this ? **this : detail_::convert<T>(constexpr_forward<V>(v));
|
|
}
|
|
|
|
# if OPTIONAL_HAS_MOVE_ACCESSORS == 1
|
|
|
|
template <class V>
|
|
OPTIONAL_MUTABLE_CONSTEXPR T value_or(V&& v) &&
|
|
{
|
|
return *this ? constexpr_move(const_cast<optional<T>&>(*this).contained_val()) : detail_::convert<T>(constexpr_forward<V>(v));
|
|
}
|
|
|
|
# else
|
|
|
|
template <class V>
|
|
T value_or(V&& v) &&
|
|
{
|
|
return *this ? constexpr_move(const_cast<optional<T>&>(*this).contained_val()) : detail_::convert<T>(constexpr_forward<V>(v));
|
|
}
|
|
|
|
# endif
|
|
|
|
# else
|
|
|
|
template <class V>
|
|
constexpr T value_or(V&& v) const
|
|
{
|
|
return *this ? **this : detail_::convert<T>(constexpr_forward<V>(v));
|
|
}
|
|
|
|
# endif
|
|
|
|
};
|
|
|
|
|
|
template <class T>
|
|
class optional<T&>
|
|
{
|
|
static_assert( !std::is_same<T, nullopt_t>::value, "bad T" );
|
|
static_assert( !std::is_same<T, in_place_t>::value, "bad T" );
|
|
T* ref;
|
|
|
|
public:
|
|
|
|
// 20.5.5.1, construction/destruction
|
|
constexpr optional() noexcept : ref(nullptr) {}
|
|
|
|
constexpr optional(nullopt_t) noexcept : ref(nullptr) {}
|
|
|
|
constexpr optional(T& v) noexcept : ref(detail_::static_addressof(v)) {}
|
|
|
|
optional(T&&) = delete;
|
|
|
|
constexpr optional(const optional& rhs) noexcept : ref(rhs.ref) {}
|
|
|
|
explicit constexpr optional(in_place_t, T& v) noexcept : ref(detail_::static_addressof(v)) {}
|
|
|
|
explicit optional(in_place_t, T&&) = delete;
|
|
|
|
~optional() = default;
|
|
|
|
// 20.5.5.2, mutation
|
|
optional& operator=(nullopt_t) noexcept {
|
|
ref = nullptr;
|
|
return *this;
|
|
}
|
|
|
|
// optional& operator=(const optional& rhs) noexcept {
|
|
// ref = rhs.ref;
|
|
// return *this;
|
|
// }
|
|
|
|
// optional& operator=(optional&& rhs) noexcept {
|
|
// ref = rhs.ref;
|
|
// return *this;
|
|
// }
|
|
|
|
template <typename U>
|
|
auto operator=(U&& rhs) noexcept
|
|
-> typename enable_if
|
|
<
|
|
is_same<typename decay<U>::type, optional<T&>>::value,
|
|
optional&
|
|
>::type
|
|
{
|
|
ref = rhs.ref;
|
|
return *this;
|
|
}
|
|
|
|
template <typename U>
|
|
auto operator=(U&& rhs) noexcept
|
|
-> typename enable_if
|
|
<
|
|
!is_same<typename decay<U>::type, optional<T&>>::value,
|
|
optional&
|
|
>::type
|
|
= delete;
|
|
|
|
void emplace(T& v) noexcept {
|
|
ref = detail_::static_addressof(v);
|
|
}
|
|
|
|
void emplace(T&&) = delete;
|
|
|
|
|
|
void swap(optional<T&>& rhs) noexcept
|
|
{
|
|
std::swap(ref, rhs.ref);
|
|
}
|
|
|
|
// 20.5.5.3, observers
|
|
constexpr T* operator->() const {
|
|
return TR2_OPTIONAL_ASSERTED_EXPRESSION(ref, ref);
|
|
}
|
|
|
|
constexpr T& operator*() const {
|
|
return TR2_OPTIONAL_ASSERTED_EXPRESSION(ref, *ref);
|
|
}
|
|
|
|
constexpr T& value() const {
|
|
return ref ? *ref : (throw bad_optional_access("bad optional access"), *ref);
|
|
}
|
|
|
|
explicit constexpr operator bool() const noexcept {
|
|
return ref != nullptr;
|
|
}
|
|
|
|
template <class V>
|
|
constexpr typename decay<T>::type value_or(V&& v) const
|
|
{
|
|
return *this ? **this : detail_::convert<typename decay<T>::type>(constexpr_forward<V>(v));
|
|
}
|
|
};
|
|
|
|
|
|
template <class T>
|
|
class optional<T&&>
|
|
{
|
|
static_assert( sizeof(T) == 0, "optional rvalue references disallowed" );
|
|
};
|
|
|
|
|
|
// 20.5.8, Relational operators
|
|
template <class T> constexpr bool operator==(const optional<T>& x, const optional<T>& y)
|
|
{
|
|
return bool(x) != bool(y) ? false : bool(x) == false ? true : *x == *y;
|
|
}
|
|
|
|
template <class T> constexpr bool operator!=(const optional<T>& x, const optional<T>& y)
|
|
{
|
|
return !(x == y);
|
|
}
|
|
|
|
template <class T> constexpr bool operator<(const optional<T>& x, const optional<T>& y)
|
|
{
|
|
return (!y) ? false : (!x) ? true : *x < *y;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>(const optional<T>& x, const optional<T>& y)
|
|
{
|
|
return (y < x);
|
|
}
|
|
|
|
template <class T> constexpr bool operator<=(const optional<T>& x, const optional<T>& y)
|
|
{
|
|
return !(y < x);
|
|
}
|
|
|
|
template <class T> constexpr bool operator>=(const optional<T>& x, const optional<T>& y)
|
|
{
|
|
return !(x < y);
|
|
}
|
|
|
|
|
|
// 20.5.9, Comparison with nullopt
|
|
template <class T> constexpr bool operator==(const optional<T>& x, nullopt_t) noexcept
|
|
{
|
|
return (!x);
|
|
}
|
|
|
|
template <class T> constexpr bool operator==(nullopt_t, const optional<T>& x) noexcept
|
|
{
|
|
return (!x);
|
|
}
|
|
|
|
template <class T> constexpr bool operator!=(const optional<T>& x, nullopt_t) noexcept
|
|
{
|
|
return bool(x);
|
|
}
|
|
|
|
template <class T> constexpr bool operator!=(nullopt_t, const optional<T>& x) noexcept
|
|
{
|
|
return bool(x);
|
|
}
|
|
|
|
template <class T> constexpr bool operator<(const optional<T>&, nullopt_t) noexcept
|
|
{
|
|
return false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<(nullopt_t, const optional<T>& x) noexcept
|
|
{
|
|
return bool(x);
|
|
}
|
|
|
|
template <class T> constexpr bool operator<=(const optional<T>& x, nullopt_t) noexcept
|
|
{
|
|
return (!x);
|
|
}
|
|
|
|
template <class T> constexpr bool operator<=(nullopt_t, const optional<T>&) noexcept
|
|
{
|
|
return true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>(const optional<T>& x, nullopt_t) noexcept
|
|
{
|
|
return bool(x);
|
|
}
|
|
|
|
template <class T> constexpr bool operator>(nullopt_t, const optional<T>&) noexcept
|
|
{
|
|
return false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>=(const optional<T>&, nullopt_t) noexcept
|
|
{
|
|
return true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>=(nullopt_t, const optional<T>& x) noexcept
|
|
{
|
|
return (!x);
|
|
}
|
|
|
|
|
|
|
|
// 20.5.10, Comparison with T
|
|
template <class T> constexpr bool operator==(const optional<T>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x == v : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator==(const T& v, const optional<T>& x)
|
|
{
|
|
return bool(x) ? v == *x : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator!=(const optional<T>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x != v : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator!=(const T& v, const optional<T>& x)
|
|
{
|
|
return bool(x) ? v != *x : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<(const optional<T>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x < v : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>(const T& v, const optional<T>& x)
|
|
{
|
|
return bool(x) ? v > *x : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>(const optional<T>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x > v : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<(const T& v, const optional<T>& x)
|
|
{
|
|
return bool(x) ? v < *x : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>=(const optional<T>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x >= v : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<=(const T& v, const optional<T>& x)
|
|
{
|
|
return bool(x) ? v <= *x : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<=(const optional<T>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x <= v : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>=(const T& v, const optional<T>& x)
|
|
{
|
|
return bool(x) ? v >= *x : true;
|
|
}
|
|
|
|
|
|
// Comparison of optional<T&> with T
|
|
template <class T> constexpr bool operator==(const optional<T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x == v : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator==(const T& v, const optional<T&>& x)
|
|
{
|
|
return bool(x) ? v == *x : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator!=(const optional<T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x != v : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator!=(const T& v, const optional<T&>& x)
|
|
{
|
|
return bool(x) ? v != *x : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<(const optional<T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x < v : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>(const T& v, const optional<T&>& x)
|
|
{
|
|
return bool(x) ? v > *x : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>(const optional<T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x > v : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<(const T& v, const optional<T&>& x)
|
|
{
|
|
return bool(x) ? v < *x : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>=(const optional<T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x >= v : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<=(const T& v, const optional<T&>& x)
|
|
{
|
|
return bool(x) ? v <= *x : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<=(const optional<T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x <= v : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>=(const T& v, const optional<T&>& x)
|
|
{
|
|
return bool(x) ? v >= *x : true;
|
|
}
|
|
|
|
// Comparison of optional<T const&> with T
|
|
template <class T> constexpr bool operator==(const optional<const T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x == v : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator==(const T& v, const optional<const T&>& x)
|
|
{
|
|
return bool(x) ? v == *x : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator!=(const optional<const T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x != v : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator!=(const T& v, const optional<const T&>& x)
|
|
{
|
|
return bool(x) ? v != *x : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<(const optional<const T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x < v : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>(const T& v, const optional<const T&>& x)
|
|
{
|
|
return bool(x) ? v > *x : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>(const optional<const T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x > v : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<(const T& v, const optional<const T&>& x)
|
|
{
|
|
return bool(x) ? v < *x : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>=(const optional<const T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x >= v : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<=(const T& v, const optional<const T&>& x)
|
|
{
|
|
return bool(x) ? v <= *x : false;
|
|
}
|
|
|
|
template <class T> constexpr bool operator<=(const optional<const T&>& x, const T& v)
|
|
{
|
|
return bool(x) ? *x <= v : true;
|
|
}
|
|
|
|
template <class T> constexpr bool operator>=(const T& v, const optional<const T&>& x)
|
|
{
|
|
return bool(x) ? v >= *x : true;
|
|
}
|
|
|
|
|
|
// 20.5.12, Specialized algorithms
|
|
template <class T>
|
|
void swap(optional<T>& x, optional<T>& y) noexcept(noexcept(x.swap(y)))
|
|
{
|
|
x.swap(y);
|
|
}
|
|
|
|
|
|
template <class T>
|
|
constexpr optional<typename decay<T>::type> make_optional(T&& v)
|
|
{
|
|
return optional<typename decay<T>::type>(constexpr_forward<T>(v));
|
|
}
|
|
|
|
template <class X>
|
|
constexpr optional<X&> make_optional(reference_wrapper<X> v)
|
|
{
|
|
return optional<X&>(v.get());
|
|
}
|
|
|
|
|
|
} // namespace std
|
|
|
|
namespace std
|
|
{
|
|
template <typename T>
|
|
struct hash<std::optional<T>>
|
|
{
|
|
typedef typename hash<T>::result_type result_type;
|
|
typedef std::optional<T> argument_type;
|
|
|
|
constexpr result_type operator()(argument_type const& arg) const {
|
|
return arg ? std::hash<T>{}(*arg) : result_type{};
|
|
}
|
|
};
|
|
|
|
template <typename T>
|
|
struct hash<std::optional<T&>>
|
|
{
|
|
typedef typename hash<T>::result_type result_type;
|
|
typedef std::optional<T&> argument_type;
|
|
|
|
constexpr result_type operator()(argument_type const& arg) const {
|
|
return arg ? std::hash<T>{}(*arg) : result_type{};
|
|
}
|
|
};
|
|
}
|
|
|
|
# undef TR2_OPTIONAL_REQUIRES
|
|
# undef TR2_OPTIONAL_ASSERTED_EXPRESSION
|
|
|
|
# endif //___OPTIONAL_HPP___
|