1e78f53d1SNikolas Klauser // -*- C++ -*- 2e78f53d1SNikolas Klauser //===----------------------------------------------------------------------===// 3e78f53d1SNikolas Klauser // 4e78f53d1SNikolas Klauser // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5e78f53d1SNikolas Klauser // See https://llvm.org/LICENSE.txt for license information. 6e78f53d1SNikolas Klauser // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7e78f53d1SNikolas Klauser // 8e78f53d1SNikolas Klauser //===----------------------------------------------------------------------===// 9e78f53d1SNikolas Klauser 10*ce777190SNikolas Klauser #ifndef _LIBCPP___CXX03___MEMORY_COMPRESSED_PAIR_H 11*ce777190SNikolas Klauser #define _LIBCPP___CXX03___MEMORY_COMPRESSED_PAIR_H 12e78f53d1SNikolas Klauser 1373fbae83SNikolas Klauser #include <__cxx03/__config> 1473fbae83SNikolas Klauser #include <__cxx03/__fwd/tuple.h> 1573fbae83SNikolas Klauser #include <__cxx03/__tuple/tuple_indices.h> 1673fbae83SNikolas Klauser #include <__cxx03/__type_traits/decay.h> 1773fbae83SNikolas Klauser #include <__cxx03/__type_traits/dependent_type.h> 1873fbae83SNikolas Klauser #include <__cxx03/__type_traits/enable_if.h> 1973fbae83SNikolas Klauser #include <__cxx03/__type_traits/is_constructible.h> 2073fbae83SNikolas Klauser #include <__cxx03/__type_traits/is_empty.h> 2173fbae83SNikolas Klauser #include <__cxx03/__type_traits/is_final.h> 2273fbae83SNikolas Klauser #include <__cxx03/__type_traits/is_same.h> 2373fbae83SNikolas Klauser #include <__cxx03/__type_traits/is_swappable.h> 2473fbae83SNikolas Klauser #include <__cxx03/__utility/forward.h> 2573fbae83SNikolas Klauser #include <__cxx03/__utility/move.h> 2673fbae83SNikolas Klauser #include <__cxx03/__utility/piecewise_construct.h> 2773fbae83SNikolas Klauser #include <__cxx03/cstddef> 28e78f53d1SNikolas Klauser 29e78f53d1SNikolas Klauser #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 30e78f53d1SNikolas Klauser # pragma GCC system_header 31e78f53d1SNikolas Klauser #endif 32e78f53d1SNikolas Klauser 33e78f53d1SNikolas Klauser _LIBCPP_PUSH_MACROS 3473fbae83SNikolas Klauser #include <__cxx03/__undef_macros> 35e78f53d1SNikolas Klauser 36e78f53d1SNikolas Klauser _LIBCPP_BEGIN_NAMESPACE_STD 37e78f53d1SNikolas Klauser 38e78f53d1SNikolas Klauser // Tag used to default initialize one or both of the pair's elements. 39e78f53d1SNikolas Klauser struct __default_init_tag {}; 40e78f53d1SNikolas Klauser struct __value_init_tag {}; 41e78f53d1SNikolas Klauser 42e78f53d1SNikolas Klauser template <class _Tp, int _Idx, bool _CanBeEmptyBase = is_empty<_Tp>::value && !__libcpp_is_final<_Tp>::value> 43e78f53d1SNikolas Klauser struct __compressed_pair_elem { 44e78f53d1SNikolas Klauser using _ParamT = _Tp; 45e78f53d1SNikolas Klauser using reference = _Tp&; 46e78f53d1SNikolas Klauser using const_reference = const _Tp&; 47e78f53d1SNikolas Klauser 48e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(__default_init_tag) {} 49e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(__value_init_tag) : __value_() {} 50e78f53d1SNikolas Klauser 51e78f53d1SNikolas Klauser template <class _Up, __enable_if_t<!is_same<__compressed_pair_elem, __decay_t<_Up> >::value, int> = 0> 52e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(_Up&& __u) 53e78f53d1SNikolas Klauser : __value_(std::forward<_Up>(__u)) {} 54e78f53d1SNikolas Klauser 55e78f53d1SNikolas Klauser #ifndef _LIBCPP_CXX03_LANG 56e78f53d1SNikolas Klauser template <class... _Args, size_t... _Indices> 57e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 explicit __compressed_pair_elem( 58e78f53d1SNikolas Klauser piecewise_construct_t, tuple<_Args...> __args, __tuple_indices<_Indices...>) 59e78f53d1SNikolas Klauser : __value_(std::forward<_Args>(std::get<_Indices>(__args))...) {} 60e78f53d1SNikolas Klauser #endif 61e78f53d1SNikolas Klauser 62e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 reference __get() _NOEXCEPT { return __value_; } 63e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR const_reference __get() const _NOEXCEPT { return __value_; } 64e78f53d1SNikolas Klauser 65e78f53d1SNikolas Klauser private: 66e78f53d1SNikolas Klauser _Tp __value_; 67e78f53d1SNikolas Klauser }; 68e78f53d1SNikolas Klauser 69e78f53d1SNikolas Klauser template <class _Tp, int _Idx> 70e78f53d1SNikolas Klauser struct __compressed_pair_elem<_Tp, _Idx, true> : private _Tp { 71e78f53d1SNikolas Klauser using _ParamT = _Tp; 72e78f53d1SNikolas Klauser using reference = _Tp&; 73e78f53d1SNikolas Klauser using const_reference = const _Tp&; 74e78f53d1SNikolas Klauser using __value_type = _Tp; 75e78f53d1SNikolas Klauser 76e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem() = default; 77e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(__default_init_tag) {} 78e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(__value_init_tag) : __value_type() {} 79e78f53d1SNikolas Klauser 80e78f53d1SNikolas Klauser template <class _Up, __enable_if_t<!is_same<__compressed_pair_elem, __decay_t<_Up> >::value, int> = 0> 81e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(_Up&& __u) 82e78f53d1SNikolas Klauser : __value_type(std::forward<_Up>(__u)) {} 83e78f53d1SNikolas Klauser 84e78f53d1SNikolas Klauser #ifndef _LIBCPP_CXX03_LANG 85e78f53d1SNikolas Klauser template <class... _Args, size_t... _Indices> 86e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 87e78f53d1SNikolas Klauser __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args, __tuple_indices<_Indices...>) 88e78f53d1SNikolas Klauser : __value_type(std::forward<_Args>(std::get<_Indices>(__args))...) {} 89e78f53d1SNikolas Klauser #endif 90e78f53d1SNikolas Klauser 91e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 reference __get() _NOEXCEPT { return *this; } 92e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR const_reference __get() const _NOEXCEPT { return *this; } 93e78f53d1SNikolas Klauser }; 94e78f53d1SNikolas Klauser 95e78f53d1SNikolas Klauser template <class _T1, class _T2> 96e78f53d1SNikolas Klauser class __compressed_pair : private __compressed_pair_elem<_T1, 0>, private __compressed_pair_elem<_T2, 1> { 97e78f53d1SNikolas Klauser public: 98e78f53d1SNikolas Klauser // NOTE: This static assert should never fire because __compressed_pair 99e78f53d1SNikolas Klauser // is *almost never* used in a scenario where it's possible for T1 == T2. 100e78f53d1SNikolas Klauser // (The exception is std::function where it is possible that the function 101e78f53d1SNikolas Klauser // object and the allocator have the same type). 102e78f53d1SNikolas Klauser static_assert( 103e78f53d1SNikolas Klauser (!is_same<_T1, _T2>::value), 104e78f53d1SNikolas Klauser "__compressed_pair cannot be instantiated when T1 and T2 are the same type; " 105e78f53d1SNikolas Klauser "The current implementation is NOT ABI-compatible with the previous implementation for this configuration"); 106e78f53d1SNikolas Klauser 107e78f53d1SNikolas Klauser using _Base1 _LIBCPP_NODEBUG = __compressed_pair_elem<_T1, 0>; 108e78f53d1SNikolas Klauser using _Base2 _LIBCPP_NODEBUG = __compressed_pair_elem<_T2, 1>; 109e78f53d1SNikolas Klauser 110e78f53d1SNikolas Klauser template <bool _Dummy = true, 111e78f53d1SNikolas Klauser __enable_if_t< __dependent_type<is_default_constructible<_T1>, _Dummy>::value && 112e78f53d1SNikolas Klauser __dependent_type<is_default_constructible<_T2>, _Dummy>::value, 113e78f53d1SNikolas Klauser int> = 0> 114e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair() 115e78f53d1SNikolas Klauser : _Base1(__value_init_tag()), _Base2(__value_init_tag()) {} 116e78f53d1SNikolas Klauser 117e78f53d1SNikolas Klauser template <class _U1, class _U2> 118e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair(_U1&& __t1, _U2&& __t2) 119e78f53d1SNikolas Klauser : _Base1(std::forward<_U1>(__t1)), _Base2(std::forward<_U2>(__t2)) {} 120e78f53d1SNikolas Klauser 121e78f53d1SNikolas Klauser #ifndef _LIBCPP_CXX03_LANG 122e78f53d1SNikolas Klauser template <class... _Args1, class... _Args2> 123e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 explicit __compressed_pair( 124e78f53d1SNikolas Klauser piecewise_construct_t __pc, tuple<_Args1...> __first_args, tuple<_Args2...> __second_args) 125e78f53d1SNikolas Klauser : _Base1(__pc, std::move(__first_args), typename __make_tuple_indices<sizeof...(_Args1)>::type()), 126e78f53d1SNikolas Klauser _Base2(__pc, std::move(__second_args), typename __make_tuple_indices<sizeof...(_Args2)>::type()) {} 127e78f53d1SNikolas Klauser #endif 128e78f53d1SNikolas Klauser 129e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 typename _Base1::reference first() _NOEXCEPT { 130e78f53d1SNikolas Klauser return static_cast<_Base1&>(*this).__get(); 131e78f53d1SNikolas Klauser } 132e78f53d1SNikolas Klauser 133e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR typename _Base1::const_reference first() const _NOEXCEPT { 134e78f53d1SNikolas Klauser return static_cast<_Base1 const&>(*this).__get(); 135e78f53d1SNikolas Klauser } 136e78f53d1SNikolas Klauser 137e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 typename _Base2::reference second() _NOEXCEPT { 138e78f53d1SNikolas Klauser return static_cast<_Base2&>(*this).__get(); 139e78f53d1SNikolas Klauser } 140e78f53d1SNikolas Klauser 141e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR typename _Base2::const_reference second() const _NOEXCEPT { 142e78f53d1SNikolas Klauser return static_cast<_Base2 const&>(*this).__get(); 143e78f53d1SNikolas Klauser } 144e78f53d1SNikolas Klauser 145e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR static _Base1* __get_first_base(__compressed_pair* __pair) _NOEXCEPT { 146e78f53d1SNikolas Klauser return static_cast<_Base1*>(__pair); 147e78f53d1SNikolas Klauser } 148e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR static _Base2* __get_second_base(__compressed_pair* __pair) _NOEXCEPT { 149e78f53d1SNikolas Klauser return static_cast<_Base2*>(__pair); 150e78f53d1SNikolas Klauser } 151e78f53d1SNikolas Klauser 152e78f53d1SNikolas Klauser _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void swap(__compressed_pair& __x) 153e78f53d1SNikolas Klauser _NOEXCEPT_(__is_nothrow_swappable_v<_T1>&& __is_nothrow_swappable_v<_T2>) { 154e78f53d1SNikolas Klauser using std::swap; 155e78f53d1SNikolas Klauser swap(first(), __x.first()); 156e78f53d1SNikolas Klauser swap(second(), __x.second()); 157e78f53d1SNikolas Klauser } 158e78f53d1SNikolas Klauser }; 159e78f53d1SNikolas Klauser 160e78f53d1SNikolas Klauser template <class _T1, class _T2> 161e78f53d1SNikolas Klauser inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void 162e78f53d1SNikolas Klauser swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y) 163e78f53d1SNikolas Klauser _NOEXCEPT_(__is_nothrow_swappable_v<_T1>&& __is_nothrow_swappable_v<_T2>) { 164e78f53d1SNikolas Klauser __x.swap(__y); 165e78f53d1SNikolas Klauser } 166e78f53d1SNikolas Klauser 167e78f53d1SNikolas Klauser _LIBCPP_END_NAMESPACE_STD 168e78f53d1SNikolas Klauser 169e78f53d1SNikolas Klauser _LIBCPP_POP_MACROS 170e78f53d1SNikolas Klauser 171*ce777190SNikolas Klauser #endif // _LIBCPP___CXX03___MEMORY_COMPRESSED_PAIR_H 172