gcc/libstdc++-v3/include/std/utility
Ville Voutilainen 5c578ae434 Implement LWG 2744 and LWG 2754.
* include/std/any (any(ValueType&&)): Constrain with __is_in_place_type.
	(any(in_place_type_t<_ValueType>, _Args&&...)): Use _Decay.
	(any(in_place_type_t<_ValueType>, initializer_list<_Up>, _Args&&...)):
	Likewise.
	(emplace(_Args&&...)): Likewise.
	(emplace(initializer_list<_Up>, _Args&&...)): Likewise.
	* include/std/utility: (__is_in_place_type_impl): New.
	(__is_in_place_type): Likewise.
	* testsuite/20_util/any/assign/emplace.cc: Add tests for decaying
	emplace.
	* testsuite/20_util/any/cons/in_place.cc: Add tests for decaying
	in_place constructor.
	* testsuite/20_util/any/misc/any_cast_neg.cc: Adjust.
	* testsuite/20_util/any/requirements.cc: Add a test for
	in_place-constructing a non-default-constructible type.

From-SVN: r239482
2016-08-15 18:06:09 +03:00

387 lines
12 KiB
C++

// <utility> -*- C++ -*-
// Copyright (C) 2001-2016 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1996,1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file include/utility
* This is a Standard C++ Library header.
*/
#ifndef _GLIBCXX_UTILITY
#define _GLIBCXX_UTILITY 1
#pragma GCC system_header
/**
* @defgroup utilities Utilities
*
* Components deemed generally useful. Includes pair, tuple,
* forward/move helpers, ratio, function object, metaprogramming and
* type traits, time, date, and memory functions.
*/
#include <bits/c++config.h>
#include <bits/stl_relops.h>
#include <bits/stl_pair.h>
#if __cplusplus >= 201103L
#include <type_traits>
#include <bits/move.h>
#include <initializer_list>
#if __cplusplus > 201402L
#include <exception>
#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/// Finds the size of a given tuple type.
template<typename _Tp>
struct tuple_size;
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2313. tuple_size should always derive from integral_constant<size_t, N>
template<typename _Tp>
struct tuple_size<const _Tp>
: integral_constant<size_t, tuple_size<_Tp>::value> { };
template<typename _Tp>
struct tuple_size<volatile _Tp>
: integral_constant<size_t, tuple_size<_Tp>::value> { };
template<typename _Tp>
struct tuple_size<const volatile _Tp>
: integral_constant<size_t, tuple_size<_Tp>::value> { };
/// Gives the type of the ith element of a given tuple type.
template<std::size_t __i, typename _Tp>
struct tuple_element;
// Duplicate of C++14's tuple_element_t for internal use in C++11 mode
template<std::size_t __i, typename _Tp>
using __tuple_element_t = typename tuple_element<__i, _Tp>::type;
template<std::size_t __i, typename _Tp>
struct tuple_element<__i, const _Tp>
{
typedef typename add_const<__tuple_element_t<__i, _Tp>>::type type;
};
template<std::size_t __i, typename _Tp>
struct tuple_element<__i, volatile _Tp>
{
typedef typename add_volatile<__tuple_element_t<__i, _Tp>>::type type;
};
template<std::size_t __i, typename _Tp>
struct tuple_element<__i, const volatile _Tp>
{
typedef typename add_cv<__tuple_element_t<__i, _Tp>>::type type;
};
#if __cplusplus > 201103L
#define __cpp_lib_tuple_element_t 201402
template<std::size_t __i, typename _Tp>
using tuple_element_t = typename tuple_element<__i, _Tp>::type;
#endif
template<typename>
struct __is_tuple_like_impl : false_type
{ };
// Various functions which give std::pair a tuple-like interface.
/// Partial specialization for std::pair
template<typename _T1, typename _T2>
struct __is_tuple_like_impl<std::pair<_T1, _T2>> : true_type
{ };
/// Partial specialization for std::pair
template<class _Tp1, class _Tp2>
struct tuple_size<std::pair<_Tp1, _Tp2>>
: public integral_constant<std::size_t, 2> { };
/// Partial specialization for std::pair
template<class _Tp1, class _Tp2>
struct tuple_element<0, std::pair<_Tp1, _Tp2>>
{ typedef _Tp1 type; };
/// Partial specialization for std::pair
template<class _Tp1, class _Tp2>
struct tuple_element<1, std::pair<_Tp1, _Tp2>>
{ typedef _Tp2 type; };
template<std::size_t _Int>
struct __pair_get;
template<>
struct __pair_get<0>
{
template<typename _Tp1, typename _Tp2>
static constexpr _Tp1&
__get(std::pair<_Tp1, _Tp2>& __pair) noexcept
{ return __pair.first; }
template<typename _Tp1, typename _Tp2>
static constexpr _Tp1&&
__move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
{ return std::forward<_Tp1>(__pair.first); }
template<typename _Tp1, typename _Tp2>
static constexpr const _Tp1&
__const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
{ return __pair.first; }
};
template<>
struct __pair_get<1>
{
template<typename _Tp1, typename _Tp2>
static constexpr _Tp2&
__get(std::pair<_Tp1, _Tp2>& __pair) noexcept
{ return __pair.second; }
template<typename _Tp1, typename _Tp2>
static constexpr _Tp2&&
__move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
{ return std::forward<_Tp2>(__pair.second); }
template<typename _Tp1, typename _Tp2>
static constexpr const _Tp2&
__const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
{ return __pair.second; }
};
template<std::size_t _Int, class _Tp1, class _Tp2>
constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
get(std::pair<_Tp1, _Tp2>& __in) noexcept
{ return __pair_get<_Int>::__get(__in); }
template<std::size_t _Int, class _Tp1, class _Tp2>
constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
get(std::pair<_Tp1, _Tp2>&& __in) noexcept
{ return __pair_get<_Int>::__move_get(std::move(__in)); }
template<std::size_t _Int, class _Tp1, class _Tp2>
constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
get(const std::pair<_Tp1, _Tp2>& __in) noexcept
{ return __pair_get<_Int>::__const_get(__in); }
#if __cplusplus > 201103L
#define __cpp_lib_tuples_by_type 201304
template <typename _Tp, typename _Up>
constexpr _Tp&
get(pair<_Tp, _Up>& __p) noexcept
{ return __p.first; }
template <typename _Tp, typename _Up>
constexpr const _Tp&
get(const pair<_Tp, _Up>& __p) noexcept
{ return __p.first; }
template <typename _Tp, typename _Up>
constexpr _Tp&&
get(pair<_Tp, _Up>&& __p) noexcept
{ return std::move(__p.first); }
template <typename _Tp, typename _Up>
constexpr _Tp&
get(pair<_Up, _Tp>& __p) noexcept
{ return __p.second; }
template <typename _Tp, typename _Up>
constexpr const _Tp&
get(const pair<_Up, _Tp>& __p) noexcept
{ return __p.second; }
template <typename _Tp, typename _Up>
constexpr _Tp&&
get(pair<_Up, _Tp>&& __p) noexcept
{ return std::move(__p.second); }
#define __cpp_lib_exchange_function 201304
/// Assign @p __new_val to @p __obj and return its previous value.
template <typename _Tp, typename _Up = _Tp>
inline _Tp
exchange(_Tp& __obj, _Up&& __new_val)
{ return std::__exchange(__obj, std::forward<_Up>(__new_val)); }
#endif
// Stores a tuple of indices. Used by tuple and pair, and by bind() to
// extract the elements in a tuple.
template<size_t... _Indexes> struct _Index_tuple { };
// Concatenates two _Index_tuples.
template<typename _Itup1, typename _Itup2> struct _Itup_cat;
template<size_t... _Ind1, size_t... _Ind2>
struct _Itup_cat<_Index_tuple<_Ind1...>, _Index_tuple<_Ind2...>>
{
using __type = _Index_tuple<_Ind1..., (_Ind2 + sizeof...(_Ind1))...>;
};
// Builds an _Index_tuple<0, 1, 2, ..., _Num-1>.
template<size_t _Num>
struct _Build_index_tuple
: _Itup_cat<typename _Build_index_tuple<_Num / 2>::__type,
typename _Build_index_tuple<_Num - _Num / 2>::__type>
{ };
template<>
struct _Build_index_tuple<1>
{
typedef _Index_tuple<0> __type;
};
template<>
struct _Build_index_tuple<0>
{
typedef _Index_tuple<> __type;
};
#if __cplusplus > 201103L
#define __cpp_lib_integer_sequence 201304
/// Class template integer_sequence
template<typename _Tp, _Tp... _Idx>
struct integer_sequence
{
typedef _Tp value_type;
static constexpr size_t size() { return sizeof...(_Idx); }
};
template<typename _Tp, _Tp _Num,
typename _ISeq = typename _Build_index_tuple<_Num>::__type>
struct _Make_integer_sequence;
template<typename _Tp, _Tp _Num, size_t... _Idx>
struct _Make_integer_sequence<_Tp, _Num, _Index_tuple<_Idx...>>
{
static_assert( _Num >= 0,
"Cannot make integer sequence of negative length" );
typedef integer_sequence<_Tp, static_cast<_Tp>(_Idx)...> __type;
};
/// Alias template make_integer_sequence
template<typename _Tp, _Tp _Num>
using make_integer_sequence
= typename _Make_integer_sequence<_Tp, _Num>::__type;
/// Alias template index_sequence
template<size_t... _Idx>
using index_sequence = integer_sequence<size_t, _Idx...>;
/// Alias template make_index_sequence
template<size_t _Num>
using make_index_sequence = make_integer_sequence<size_t, _Num>;
/// Alias template index_sequence_for
template<typename... _Types>
using index_sequence_for = make_index_sequence<sizeof...(_Types)>;
#endif
#if __cplusplus > 201402L
struct in_place_tag {
in_place_tag() = delete;
};
struct __in_place;
template<typename _Tp> struct __in_place_type;
template<size_t _Idx> struct __in_place_index;
using in_place_t = in_place_tag(&)(__in_place*);
template <class _Tp>
using in_place_type_t = in_place_tag(&)(__in_place_type<_Tp>*);
template <int _Idx>
using in_place_index_t = in_place_tag(&)(__in_place_index<_Idx>*);
inline in_place_tag in_place(__in_place*) {terminate();}
template <class _Tp>
in_place_tag in_place(__in_place_type<_Tp>*) {terminate();}
template <size_t _Idx>
in_place_tag in_place(__in_place_index<_Idx>*) {terminate();}
template<typename>
struct __is_in_place_type_impl : false_type
{ };
template<typename _Tp>
struct __is_in_place_type_impl<in_place_type_t<_Tp>> : true_type
{ };
template<typename _Tp>
struct __is_in_place_type
: public __is_in_place_type_impl<_Tp>
{ };
#define __cpp_lib_as_const 201510
template<typename _Tp>
constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
template<typename _Tp>
void as_const(const _Tp&&) = delete;
#endif // C++17
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif
#endif /* _GLIBCXX_UTILITY */