705 lines
19 KiB
C++
705 lines
19 KiB
C++
// C++0x type_traits -*- C++ -*-
|
|
|
|
// Copyright (C) 2007, 2008, 2009, 2010 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/>.
|
|
|
|
/** @file include/type_traits
|
|
* This is a Standard C++ Library header.
|
|
*/
|
|
|
|
#ifndef _GLIBCXX_TYPE_TRAITS
|
|
#define _GLIBCXX_TYPE_TRAITS 1
|
|
|
|
#pragma GCC system_header
|
|
|
|
#ifndef __GXX_EXPERIMENTAL_CXX0X__
|
|
# include <bits/c++0x_warning.h>
|
|
#else
|
|
|
|
#if defined(_GLIBCXX_INCLUDE_AS_TR1)
|
|
# error C++0x header cannot be included from TR1 header
|
|
#endif
|
|
|
|
#include <bits/c++config.h>
|
|
|
|
#if defined(_GLIBCXX_INCLUDE_AS_CXX0X)
|
|
# include <tr1_impl/type_traits>
|
|
#else
|
|
# define _GLIBCXX_INCLUDE_AS_CXX0X
|
|
# define _GLIBCXX_BEGIN_NAMESPACE_TR1
|
|
# define _GLIBCXX_END_NAMESPACE_TR1
|
|
# define _GLIBCXX_TR1
|
|
# include <tr1_impl/type_traits>
|
|
# undef _GLIBCXX_TR1
|
|
# undef _GLIBCXX_END_NAMESPACE_TR1
|
|
# undef _GLIBCXX_BEGIN_NAMESPACE_TR1
|
|
# undef _GLIBCXX_INCLUDE_AS_CXX0X
|
|
#endif
|
|
|
|
namespace std
|
|
{
|
|
/**
|
|
* @addtogroup metaprogramming
|
|
* @{
|
|
*/
|
|
|
|
// Primary classification traits.
|
|
|
|
/// is_lvalue_reference
|
|
template<typename>
|
|
struct is_lvalue_reference
|
|
: public false_type { };
|
|
|
|
template<typename _Tp>
|
|
struct is_lvalue_reference<_Tp&>
|
|
: public true_type { };
|
|
|
|
/// is_rvalue_reference
|
|
template<typename>
|
|
struct is_rvalue_reference
|
|
: public false_type { };
|
|
|
|
template<typename _Tp>
|
|
struct is_rvalue_reference<_Tp&&>
|
|
: public true_type { };
|
|
|
|
// Secondary classification traits.
|
|
|
|
/// is_reference
|
|
template<typename _Tp>
|
|
struct is_reference
|
|
: public integral_constant<bool, (is_lvalue_reference<_Tp>::value
|
|
|| is_rvalue_reference<_Tp>::value)>
|
|
{ };
|
|
|
|
// Reference transformations.
|
|
|
|
/// remove_reference
|
|
template<typename _Tp>
|
|
struct remove_reference
|
|
{ typedef _Tp type; };
|
|
|
|
template<typename _Tp>
|
|
struct remove_reference<_Tp&>
|
|
{ typedef _Tp type; };
|
|
|
|
template<typename _Tp>
|
|
struct remove_reference<_Tp&&>
|
|
{ typedef _Tp type; };
|
|
|
|
template<typename _Tp,
|
|
bool = !is_reference<_Tp>::value && !is_void<_Tp>::value,
|
|
bool = is_rvalue_reference<_Tp>::value>
|
|
struct __add_lvalue_reference_helper
|
|
{ typedef _Tp type; };
|
|
|
|
template<typename _Tp>
|
|
struct __add_lvalue_reference_helper<_Tp, true, false>
|
|
{ typedef _Tp& type; };
|
|
|
|
template<typename _Tp>
|
|
struct __add_lvalue_reference_helper<_Tp, false, true>
|
|
{ typedef typename remove_reference<_Tp>::type& type; };
|
|
|
|
/// add_lvalue_reference
|
|
template<typename _Tp>
|
|
struct add_lvalue_reference
|
|
: public __add_lvalue_reference_helper<_Tp>
|
|
{ };
|
|
|
|
template<typename _Tp,
|
|
bool = !is_reference<_Tp>::value && !is_void<_Tp>::value>
|
|
struct __add_rvalue_reference_helper
|
|
{ typedef _Tp type; };
|
|
|
|
template<typename _Tp>
|
|
struct __add_rvalue_reference_helper<_Tp, true>
|
|
{ typedef _Tp&& type; };
|
|
|
|
/// add_rvalue_reference
|
|
template<typename _Tp>
|
|
struct add_rvalue_reference
|
|
: public __add_rvalue_reference_helper<_Tp>
|
|
{ };
|
|
|
|
// Scalar properties and transformations.
|
|
|
|
template<typename _Tp,
|
|
bool = is_integral<_Tp>::value,
|
|
bool = is_floating_point<_Tp>::value>
|
|
struct __is_signed_helper
|
|
: public false_type { };
|
|
|
|
template<typename _Tp>
|
|
struct __is_signed_helper<_Tp, false, true>
|
|
: public true_type { };
|
|
|
|
template<typename _Tp>
|
|
struct __is_signed_helper<_Tp, true, false>
|
|
: public integral_constant<bool, static_cast<bool>(_Tp(-1) < _Tp(0))>
|
|
{ };
|
|
|
|
/// is_signed
|
|
template<typename _Tp>
|
|
struct is_signed
|
|
: public integral_constant<bool, __is_signed_helper<_Tp>::value>
|
|
{ };
|
|
|
|
/// is_unsigned
|
|
template<typename _Tp>
|
|
struct is_unsigned
|
|
: public integral_constant<bool, (is_arithmetic<_Tp>::value
|
|
&& !is_signed<_Tp>::value)>
|
|
{ };
|
|
|
|
// Member introspection.
|
|
|
|
/// is_trivial
|
|
template<typename _Tp>
|
|
struct is_trivial
|
|
: public integral_constant<bool, __is_trivial(_Tp)>
|
|
{ };
|
|
|
|
/// is_standard_layout
|
|
template<typename _Tp>
|
|
struct is_standard_layout
|
|
: public integral_constant<bool, __is_standard_layout(_Tp)>
|
|
{ };
|
|
|
|
/// is_pod
|
|
// Could use is_standard_layout && is_trivial instead of the builtin.
|
|
template<typename _Tp>
|
|
struct is_pod
|
|
: public integral_constant<bool, __is_pod(_Tp)>
|
|
{ };
|
|
|
|
template<typename _Tp>
|
|
typename add_rvalue_reference<_Tp>::type declval() noexcept;
|
|
|
|
template<typename _Tp, typename... _Args>
|
|
class __is_constructible_helper
|
|
: public __sfinae_types
|
|
{
|
|
template<typename _Tp1, typename... _Args1>
|
|
static decltype(_Tp1(declval<_Args1>()...), __one()) __test(int);
|
|
|
|
template<typename, typename...>
|
|
static __two __test(...);
|
|
|
|
public:
|
|
static const bool __value = sizeof(__test<_Tp, _Args...>(0)) == 1;
|
|
};
|
|
|
|
template<typename _Tp, typename _Arg>
|
|
class __is_constructible_helper<_Tp, _Arg>
|
|
: public __sfinae_types
|
|
{
|
|
template<typename _Tp1, typename _Arg1>
|
|
static decltype(static_cast<_Tp1>(declval<_Arg1>()), __one())
|
|
__test(int);
|
|
|
|
template<typename, typename>
|
|
static __two __test(...);
|
|
|
|
public:
|
|
static const bool __value = sizeof(__test<_Tp, _Arg>(0)) == 1;
|
|
};
|
|
|
|
/// is_constructible
|
|
// XXX FIXME
|
|
// The C++0x specifications require front-end support, see N2255.
|
|
template<typename _Tp, typename... _Args>
|
|
struct is_constructible
|
|
: public integral_constant<bool,
|
|
__is_constructible_helper<_Tp,
|
|
_Args...>::__value>
|
|
{ };
|
|
|
|
template<bool, typename _Tp, typename... _Args>
|
|
struct __is_nt_constructible_helper
|
|
{ static const bool __value = false; };
|
|
|
|
template<typename _Tp, typename... _Args>
|
|
struct __is_nt_constructible_helper<true, _Tp, _Args...>
|
|
{ static const bool __value = noexcept(_Tp(declval<_Args>()...)); };
|
|
|
|
template<typename _Tp, typename _Arg>
|
|
struct __is_nt_constructible_helper<true, _Tp, _Arg>
|
|
{
|
|
static const bool __value = noexcept(static_cast<_Tp>(declval<_Arg>()));
|
|
};
|
|
|
|
/// is_nothrow_constructible
|
|
template<typename _Tp, typename... _Args>
|
|
struct is_nothrow_constructible
|
|
: public integral_constant<bool,
|
|
__is_nt_constructible_helper<is_constructible<_Tp, _Args...>::value,
|
|
_Tp, _Args...>::__value>
|
|
{ };
|
|
|
|
/// has_trivial_default_constructor
|
|
template<typename _Tp>
|
|
struct has_trivial_default_constructor
|
|
: public integral_constant<bool, __has_trivial_constructor(_Tp)>
|
|
{ };
|
|
|
|
/// has_trivial_copy_constructor
|
|
template<typename _Tp>
|
|
struct has_trivial_copy_constructor
|
|
: public integral_constant<bool, __has_trivial_copy(_Tp)>
|
|
{ };
|
|
|
|
/// has_trivial_copy_assign
|
|
template<typename _Tp>
|
|
struct has_trivial_copy_assign
|
|
: public integral_constant<bool, __has_trivial_assign(_Tp)>
|
|
{ };
|
|
|
|
/// has_trivial_destructor
|
|
template<typename _Tp>
|
|
struct has_trivial_destructor
|
|
: public integral_constant<bool, __has_trivial_destructor(_Tp)>
|
|
{ };
|
|
|
|
/// has_nothrow_default_constructor
|
|
template<typename _Tp>
|
|
struct has_nothrow_default_constructor
|
|
: public integral_constant<bool, __has_nothrow_constructor(_Tp)>
|
|
{ };
|
|
|
|
/// has_nothrow_copy_constructor
|
|
template<typename _Tp>
|
|
struct has_nothrow_copy_constructor
|
|
: public integral_constant<bool, __has_nothrow_copy(_Tp)>
|
|
{ };
|
|
|
|
/// has_nothrow_copy_assign
|
|
template<typename _Tp>
|
|
struct has_nothrow_copy_assign
|
|
: public integral_constant<bool, __has_nothrow_assign(_Tp)>
|
|
{ };
|
|
|
|
// Relationships between types.
|
|
|
|
/// is_base_of
|
|
template<typename _Base, typename _Derived>
|
|
struct is_base_of
|
|
: public integral_constant<bool, __is_base_of(_Base, _Derived)>
|
|
{ };
|
|
|
|
template<typename _From, typename _To,
|
|
bool = (is_void<_From>::value || is_function<_To>::value
|
|
|| is_array<_To>::value)>
|
|
struct __is_convertible_helper
|
|
{ static const bool __value = is_void<_To>::value; };
|
|
|
|
template<typename _From, typename _To>
|
|
class __is_convertible_helper<_From, _To, false>
|
|
: public __sfinae_types
|
|
{
|
|
template<typename _To1>
|
|
static void __test_aux(_To1);
|
|
|
|
template<typename _From1, typename _To1>
|
|
static decltype(__test_aux<_To1>(std::declval<_From1>()), __one())
|
|
__test(int);
|
|
|
|
template<typename, typename>
|
|
static __two __test(...);
|
|
|
|
public:
|
|
static const bool __value = sizeof(__test<_From, _To>(0)) == 1;
|
|
};
|
|
|
|
/// is_convertible
|
|
// XXX FIXME
|
|
// The C++0x specifications require front-end support, see N2255.
|
|
template<typename _From, typename _To>
|
|
struct is_convertible
|
|
: public integral_constant<bool,
|
|
__is_convertible_helper<_From, _To>::__value>
|
|
{ };
|
|
|
|
/// is_explicitly_convertible
|
|
template<typename _From, typename _To>
|
|
struct is_explicitly_convertible
|
|
: public is_constructible<_To, _From>
|
|
{ };
|
|
|
|
template<std::size_t _Len>
|
|
struct __aligned_storage_msa
|
|
{
|
|
union __type
|
|
{
|
|
unsigned char __data[_Len];
|
|
struct __attribute__((__aligned__)) { } __align;
|
|
};
|
|
};
|
|
|
|
/**
|
|
* @brief Alignment type.
|
|
*
|
|
* The value of _Align is a default-alignment which shall be the
|
|
* most stringent alignment requirement for any C++ object type
|
|
* whose size is no greater than _Len (3.9). The member typedef
|
|
* type shall be a POD type suitable for use as uninitialized
|
|
* storage for any object whose size is at most _Len and whose
|
|
* alignment is a divisor of _Align.
|
|
*/
|
|
template<std::size_t _Len, std::size_t _Align =
|
|
__alignof__(typename __aligned_storage_msa<_Len>::__type)>
|
|
struct aligned_storage
|
|
{
|
|
union type
|
|
{
|
|
unsigned char __data[_Len];
|
|
struct __attribute__((__aligned__((_Align)))) { } __align;
|
|
};
|
|
};
|
|
|
|
|
|
// Define a nested type if some predicate holds.
|
|
// Primary template.
|
|
/// enable_if
|
|
template<bool, typename _Tp = void>
|
|
struct enable_if
|
|
{ };
|
|
|
|
// Partial specialization for true.
|
|
template<typename _Tp>
|
|
struct enable_if<true, _Tp>
|
|
{ typedef _Tp type; };
|
|
|
|
|
|
// A conditional expression, but for types. If true, first, if false, second.
|
|
// Primary template.
|
|
/// conditional
|
|
template<bool _Cond, typename _Iftrue, typename _Iffalse>
|
|
struct conditional
|
|
{ typedef _Iftrue type; };
|
|
|
|
// Partial specialization for false.
|
|
template<typename _Iftrue, typename _Iffalse>
|
|
struct conditional<false, _Iftrue, _Iffalse>
|
|
{ typedef _Iffalse type; };
|
|
|
|
|
|
// Decay trait for arrays and functions, used for perfect forwarding
|
|
// in make_pair, make_tuple, etc.
|
|
template<typename _Up,
|
|
bool _IsArray = is_array<_Up>::value,
|
|
bool _IsFunction = is_function<_Up>::value>
|
|
struct __decay_selector;
|
|
|
|
// NB: DR 705.
|
|
template<typename _Up>
|
|
struct __decay_selector<_Up, false, false>
|
|
{ typedef typename remove_cv<_Up>::type __type; };
|
|
|
|
template<typename _Up>
|
|
struct __decay_selector<_Up, true, false>
|
|
{ typedef typename remove_extent<_Up>::type* __type; };
|
|
|
|
template<typename _Up>
|
|
struct __decay_selector<_Up, false, true>
|
|
{ typedef typename add_pointer<_Up>::type __type; };
|
|
|
|
/// decay
|
|
template<typename _Tp>
|
|
class decay
|
|
{
|
|
typedef typename remove_reference<_Tp>::type __remove_type;
|
|
|
|
public:
|
|
typedef typename __decay_selector<__remove_type>::__type type;
|
|
};
|
|
|
|
template<typename _Tp>
|
|
class reference_wrapper;
|
|
|
|
// Helper which adds a reference to a type when given a reference_wrapper
|
|
template<typename _Tp>
|
|
struct __strip_reference_wrapper
|
|
{
|
|
typedef _Tp __type;
|
|
};
|
|
|
|
template<typename _Tp>
|
|
struct __strip_reference_wrapper<reference_wrapper<_Tp> >
|
|
{
|
|
typedef _Tp& __type;
|
|
};
|
|
|
|
template<typename _Tp>
|
|
struct __strip_reference_wrapper<const reference_wrapper<_Tp> >
|
|
{
|
|
typedef _Tp& __type;
|
|
};
|
|
|
|
template<typename _Tp>
|
|
struct __decay_and_strip
|
|
{
|
|
typedef typename __strip_reference_wrapper<
|
|
typename decay<_Tp>::type>::__type __type;
|
|
};
|
|
|
|
|
|
// Utility for constructing identically cv-qualified types.
|
|
template<typename _Unqualified, bool _IsConst, bool _IsVol>
|
|
struct __cv_selector;
|
|
|
|
template<typename _Unqualified>
|
|
struct __cv_selector<_Unqualified, false, false>
|
|
{ typedef _Unqualified __type; };
|
|
|
|
template<typename _Unqualified>
|
|
struct __cv_selector<_Unqualified, false, true>
|
|
{ typedef volatile _Unqualified __type; };
|
|
|
|
template<typename _Unqualified>
|
|
struct __cv_selector<_Unqualified, true, false>
|
|
{ typedef const _Unqualified __type; };
|
|
|
|
template<typename _Unqualified>
|
|
struct __cv_selector<_Unqualified, true, true>
|
|
{ typedef const volatile _Unqualified __type; };
|
|
|
|
template<typename _Qualified, typename _Unqualified,
|
|
bool _IsConst = is_const<_Qualified>::value,
|
|
bool _IsVol = is_volatile<_Qualified>::value>
|
|
class __match_cv_qualifiers
|
|
{
|
|
typedef __cv_selector<_Unqualified, _IsConst, _IsVol> __match;
|
|
|
|
public:
|
|
typedef typename __match::__type __type;
|
|
};
|
|
|
|
|
|
// Utility for finding the unsigned versions of signed integral types.
|
|
template<typename _Tp>
|
|
struct __make_unsigned
|
|
{ typedef _Tp __type; };
|
|
|
|
template<>
|
|
struct __make_unsigned<char>
|
|
{ typedef unsigned char __type; };
|
|
|
|
template<>
|
|
struct __make_unsigned<signed char>
|
|
{ typedef unsigned char __type; };
|
|
|
|
template<>
|
|
struct __make_unsigned<short>
|
|
{ typedef unsigned short __type; };
|
|
|
|
template<>
|
|
struct __make_unsigned<int>
|
|
{ typedef unsigned int __type; };
|
|
|
|
template<>
|
|
struct __make_unsigned<long>
|
|
{ typedef unsigned long __type; };
|
|
|
|
template<>
|
|
struct __make_unsigned<long long>
|
|
{ typedef unsigned long long __type; };
|
|
|
|
|
|
// Select between integral and enum: not possible to be both.
|
|
template<typename _Tp,
|
|
bool _IsInt = is_integral<_Tp>::value,
|
|
bool _IsEnum = is_enum<_Tp>::value>
|
|
class __make_unsigned_selector;
|
|
|
|
template<typename _Tp>
|
|
class __make_unsigned_selector<_Tp, true, false>
|
|
{
|
|
typedef __make_unsigned<typename remove_cv<_Tp>::type> __unsignedt;
|
|
typedef typename __unsignedt::__type __unsigned_type;
|
|
typedef __match_cv_qualifiers<_Tp, __unsigned_type> __cv_unsigned;
|
|
|
|
public:
|
|
typedef typename __cv_unsigned::__type __type;
|
|
};
|
|
|
|
template<typename _Tp>
|
|
class __make_unsigned_selector<_Tp, false, true>
|
|
{
|
|
// With -fshort-enums, an enum may be as small as a char.
|
|
typedef unsigned char __smallest;
|
|
static const bool __b0 = sizeof(_Tp) <= sizeof(__smallest);
|
|
static const bool __b1 = sizeof(_Tp) <= sizeof(unsigned short);
|
|
static const bool __b2 = sizeof(_Tp) <= sizeof(unsigned int);
|
|
typedef conditional<__b2, unsigned int, unsigned long> __cond2;
|
|
typedef typename __cond2::type __cond2_type;
|
|
typedef conditional<__b1, unsigned short, __cond2_type> __cond1;
|
|
typedef typename __cond1::type __cond1_type;
|
|
|
|
public:
|
|
typedef typename conditional<__b0, __smallest, __cond1_type>::type __type;
|
|
};
|
|
|
|
// Given an integral/enum type, return the corresponding unsigned
|
|
// integer type.
|
|
// Primary template.
|
|
/// make_unsigned
|
|
template<typename _Tp>
|
|
struct make_unsigned
|
|
{ typedef typename __make_unsigned_selector<_Tp>::__type type; };
|
|
|
|
// Integral, but don't define.
|
|
template<>
|
|
struct make_unsigned<bool>;
|
|
|
|
|
|
// Utility for finding the signed versions of unsigned integral types.
|
|
template<typename _Tp>
|
|
struct __make_signed
|
|
{ typedef _Tp __type; };
|
|
|
|
template<>
|
|
struct __make_signed<char>
|
|
{ typedef signed char __type; };
|
|
|
|
template<>
|
|
struct __make_signed<unsigned char>
|
|
{ typedef signed char __type; };
|
|
|
|
template<>
|
|
struct __make_signed<unsigned short>
|
|
{ typedef signed short __type; };
|
|
|
|
template<>
|
|
struct __make_signed<unsigned int>
|
|
{ typedef signed int __type; };
|
|
|
|
template<>
|
|
struct __make_signed<unsigned long>
|
|
{ typedef signed long __type; };
|
|
|
|
template<>
|
|
struct __make_signed<unsigned long long>
|
|
{ typedef signed long long __type; };
|
|
|
|
|
|
// Select between integral and enum: not possible to be both.
|
|
template<typename _Tp,
|
|
bool _IsInt = is_integral<_Tp>::value,
|
|
bool _IsEnum = is_enum<_Tp>::value>
|
|
class __make_signed_selector;
|
|
|
|
template<typename _Tp>
|
|
class __make_signed_selector<_Tp, true, false>
|
|
{
|
|
typedef __make_signed<typename remove_cv<_Tp>::type> __signedt;
|
|
typedef typename __signedt::__type __signed_type;
|
|
typedef __match_cv_qualifiers<_Tp, __signed_type> __cv_signed;
|
|
|
|
public:
|
|
typedef typename __cv_signed::__type __type;
|
|
};
|
|
|
|
template<typename _Tp>
|
|
class __make_signed_selector<_Tp, false, true>
|
|
{
|
|
// With -fshort-enums, an enum may be as small as a char.
|
|
typedef signed char __smallest;
|
|
static const bool __b0 = sizeof(_Tp) <= sizeof(__smallest);
|
|
static const bool __b1 = sizeof(_Tp) <= sizeof(signed short);
|
|
static const bool __b2 = sizeof(_Tp) <= sizeof(signed int);
|
|
typedef conditional<__b2, signed int, signed long> __cond2;
|
|
typedef typename __cond2::type __cond2_type;
|
|
typedef conditional<__b1, signed short, __cond2_type> __cond1;
|
|
typedef typename __cond1::type __cond1_type;
|
|
|
|
public:
|
|
typedef typename conditional<__b0, __smallest, __cond1_type>::type __type;
|
|
};
|
|
|
|
// Given an integral/enum type, return the corresponding signed
|
|
// integer type.
|
|
// Primary template.
|
|
/// make_signed
|
|
template<typename _Tp>
|
|
struct make_signed
|
|
{ typedef typename __make_signed_selector<_Tp>::__type type; };
|
|
|
|
// Integral, but don't define.
|
|
template<>
|
|
struct make_signed<bool>;
|
|
|
|
/// common_type
|
|
template<typename... _Tp>
|
|
struct common_type;
|
|
|
|
template<typename _Tp>
|
|
struct common_type<_Tp>
|
|
{ typedef _Tp type; };
|
|
|
|
template<typename _Tp, typename _Up>
|
|
struct common_type<_Tp, _Up>
|
|
{ typedef decltype(true ? declval<_Tp>() : declval<_Up>()) type; };
|
|
|
|
template<typename _Tp, typename _Up, typename... _Vp>
|
|
struct common_type<_Tp, _Up, _Vp...>
|
|
{
|
|
typedef typename
|
|
common_type<typename common_type<_Tp, _Up>::type, _Vp...>::type type;
|
|
};
|
|
|
|
/// declval
|
|
template<typename _Tp>
|
|
struct __declval_protector
|
|
{
|
|
static const bool __stop = false;
|
|
static typename add_rvalue_reference<_Tp>::type __delegate();
|
|
};
|
|
|
|
template<typename _Tp>
|
|
inline typename add_rvalue_reference<_Tp>::type
|
|
declval() noexcept
|
|
{
|
|
static_assert(__declval_protector<_Tp>::__stop,
|
|
"declval() must not be used!");
|
|
return __declval_protector<_Tp>::__delegate();
|
|
}
|
|
|
|
/// result_of
|
|
template<typename _Signature>
|
|
class result_of;
|
|
|
|
template<typename _Functor, typename... _ArgTypes>
|
|
struct result_of<_Functor(_ArgTypes...)>
|
|
{
|
|
typedef
|
|
decltype( std::declval<_Functor>()(std::declval<_ArgTypes>()...) )
|
|
type;
|
|
};
|
|
|
|
// @} group metaprogramming
|
|
}
|
|
|
|
#endif // __GXX_EXPERIMENTAL_CXX0X__
|
|
|
|
#endif // _GLIBCXX_TYPE_TRAITS
|