// -*- C++ -*- //===----------------------------------------------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #ifndef _LIBCPP___MEMORY_COMPRESSED_PAIR_H #define _LIBCPP___MEMORY_COMPRESSED_PAIR_H #include <__config> #include <__fwd/get.h> #include <__fwd/tuple.h> #include <__tuple/tuple_indices.h> #include <__type_traits/decay.h> #include <__type_traits/dependent_type.h> #include <__type_traits/enable_if.h> #include <__type_traits/is_default_constructible.h> #include <__type_traits/is_empty.h> #include <__type_traits/is_final.h> #include <__type_traits/is_same.h> #include <__type_traits/is_swappable.h> #include <__utility/forward.h> #include <__utility/move.h> #include <__utility/piecewise_construct.h> #include #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) # pragma GCC system_header #endif _LIBCPP_PUSH_MACROS #include <__undef_macros> _LIBCPP_BEGIN_NAMESPACE_STD // Tag used to default initialize one or both of the pair's elements. struct __default_init_tag {}; struct __value_init_tag {}; template ::value && !__libcpp_is_final<_Tp>::value> struct __compressed_pair_elem { using _ParamT = _Tp; using reference = _Tp&; using const_reference = const _Tp&; _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(__default_init_tag) {} _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(__value_init_tag) : __value_() {} template >::value> > _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(_Up&& __u) : __value_(std::forward<_Up>(__u)) {} #ifndef _LIBCPP_CXX03_LANG template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 explicit __compressed_pair_elem( piecewise_construct_t, tuple<_Args...> __args, __tuple_indices<_Indices...>) : __value_(std::forward<_Args>(std::get<_Indices>(__args))...) {} #endif _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 reference __get() _NOEXCEPT { return __value_; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR const_reference __get() const _NOEXCEPT { return __value_; } private: _Tp __value_; }; template struct __compressed_pair_elem<_Tp, _Idx, true> : private _Tp { using _ParamT = _Tp; using reference = _Tp&; using const_reference = const _Tp&; using __value_type = _Tp; _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem() = default; _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(__default_init_tag) {} _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(__value_init_tag) : __value_type() {} template >::value> > _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair_elem(_Up&& __u) : __value_type(std::forward<_Up>(__u)) {} #ifndef _LIBCPP_CXX03_LANG template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args, __tuple_indices<_Indices...>) : __value_type(std::forward<_Args>(std::get<_Indices>(__args))...) {} #endif _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 reference __get() _NOEXCEPT { return *this; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR const_reference __get() const _NOEXCEPT { return *this; } }; template class __compressed_pair : private __compressed_pair_elem<_T1, 0>, private __compressed_pair_elem<_T2, 1> { public: // NOTE: This static assert should never fire because __compressed_pair // is *almost never* used in a scenario where it's possible for T1 == T2. // (The exception is std::function where it is possible that the function // object and the allocator have the same type). static_assert( (!is_same<_T1, _T2>::value), "__compressed_pair cannot be instantiated when T1 and T2 are the same type; " "The current implementation is NOT ABI-compatible with the previous implementation for this configuration"); using _Base1 _LIBCPP_NODEBUG = __compressed_pair_elem<_T1, 0>; using _Base2 _LIBCPP_NODEBUG = __compressed_pair_elem<_T2, 1>; template , _Dummy>::value && __dependent_type, _Dummy>::value > > _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair() : _Base1(__value_init_tag()), _Base2(__value_init_tag()) {} template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __compressed_pair(_U1&& __t1, _U2&& __t2) : _Base1(std::forward<_U1>(__t1)), _Base2(std::forward<_U2>(__t2)) {} #ifndef _LIBCPP_CXX03_LANG template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 explicit __compressed_pair( piecewise_construct_t __pc, tuple<_Args1...> __first_args, tuple<_Args2...> __second_args) : _Base1(__pc, std::move(__first_args), typename __make_tuple_indices::type()), _Base2(__pc, std::move(__second_args), typename __make_tuple_indices::type()) {} #endif _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 typename _Base1::reference first() _NOEXCEPT { return static_cast<_Base1&>(*this).__get(); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR typename _Base1::const_reference first() const _NOEXCEPT { return static_cast<_Base1 const&>(*this).__get(); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 typename _Base2::reference second() _NOEXCEPT { return static_cast<_Base2&>(*this).__get(); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR typename _Base2::const_reference second() const _NOEXCEPT { return static_cast<_Base2 const&>(*this).__get(); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR static _Base1* __get_first_base(__compressed_pair* __pair) _NOEXCEPT { return static_cast<_Base1*>(__pair); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR static _Base2* __get_second_base(__compressed_pair* __pair) _NOEXCEPT { return static_cast<_Base2*>(__pair); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void swap(__compressed_pair& __x) _NOEXCEPT_(__is_nothrow_swappable<_T1>::value&& __is_nothrow_swappable<_T2>::value) { using std::swap; swap(first(), __x.first()); swap(second(), __x.second()); } }; template inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y) _NOEXCEPT_(__is_nothrow_swappable<_T1>::value&& __is_nothrow_swappable<_T2>::value) { __x.swap(__y); } _LIBCPP_END_NAMESPACE_STD _LIBCPP_POP_MACROS #endif // _LIBCPP___MEMORY_COMPRESSED_PAIR_H