// C++11 <type_traits> -*- C++ -*- // Copyright (C) 2007-2013 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 #if __cplusplus < 201103L # include <bits/c++0x_warning.h> #else #include <bits/c++config.h> namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION /** * @defgroup metaprogramming Metaprogramming * @ingroup utilities * * Template utilities for compile-time introspection and modification, * including type classification traits, type property inspection traits * and type transformation traits. * * @{ */ /// integral_constant template<typename _Tp, _Tp __v> struct integral_constant { static constexpr _Tp value = __v; typedef _Tp value_type; typedef integral_constant<_Tp, __v> type; constexpr operator value_type() { return value; } }; template<typename _Tp, _Tp __v> constexpr _Tp integral_constant<_Tp, __v>::value; /// The type used as a compile-time boolean with true value. typedef integral_constant<bool, true> true_type; /// The type used as a compile-time boolean with false value. typedef integral_constant<bool, false> false_type; // Meta programming helper types. template<bool, typename, typename> struct conditional; template<typename...> struct __or_; template<> struct __or_<> : public false_type { }; template<typename _B1> struct __or_<_B1> : public _B1 { }; template<typename _B1, typename _B2> struct __or_<_B1, _B2> : public conditional<_B1::value, _B1, _B2>::type { }; template<typename _B1, typename _B2, typename _B3, typename... _Bn> struct __or_<_B1, _B2, _B3, _Bn...> : public conditional<_B1::value, _B1, __or_<_B2, _B3, _Bn...>>::type { }; template<typename...> struct __and_; template<> struct __and_<> : public true_type { }; template<typename _B1> struct __and_<_B1> : public _B1 { }; template<typename _B1, typename _B2> struct __and_<_B1, _B2> : public conditional<_B1::value, _B2, _B1>::type { }; template<typename _B1, typename _B2, typename _B3, typename... _Bn> struct __and_<_B1, _B2, _B3, _Bn...> : public conditional<_B1::value, __and_<_B2, _B3, _Bn...>, _B1>::type { }; template<typename _Pp> struct __not_ : public integral_constant<bool, !_Pp::value> { }; struct __sfinae_types { typedef char __one; typedef struct { char __arr[2]; } __two; }; // For several sfinae-friendly trait implementations we transport both the // result information (as the member type) and the failure information (no // member type). This is very similar to std::enable_if, but we cannot use // them, because we need to derive from them as an implementation detail. template<typename _Tp> struct __success_type { typedef _Tp type; }; struct __failure_type { }; // Primary type categories. template<typename> struct remove_cv; template<typename> struct __is_void_helper : public false_type { }; template<> struct __is_void_helper<void> : public true_type { }; /// is_void template<typename _Tp> struct is_void : public integral_constant<bool, (__is_void_helper<typename remove_cv<_Tp>::type>::value)> { }; template<typename> struct __is_integral_helper : public false_type { }; template<> struct __is_integral_helper<bool> : public true_type { }; template<> struct __is_integral_helper<char> : public true_type { }; template<> struct __is_integral_helper<signed char> : public true_type { }; template<> struct __is_integral_helper<unsigned char> : public true_type { }; #ifdef _GLIBCXX_USE_WCHAR_T template<> struct __is_integral_helper<wchar_t> : public true_type { }; #endif template<> struct __is_integral_helper<char16_t> : public true_type { }; template<> struct __is_integral_helper<char32_t> : public true_type { }; template<> struct __is_integral_helper<short> : public true_type { }; template<> struct __is_integral_helper<unsigned short> : public true_type { }; template<> struct __is_integral_helper<int> : public true_type { }; template<> struct __is_integral_helper<unsigned int> : public true_type { }; template<> struct __is_integral_helper<long> : public true_type { }; template<> struct __is_integral_helper<unsigned long> : public true_type { }; template<> struct __is_integral_helper<long long> : public true_type { }; template<> struct __is_integral_helper<unsigned long long> : public true_type { }; #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_INT128) template<> struct __is_integral_helper<__int128> : public true_type { }; template<> struct __is_integral_helper<unsigned __int128> : public true_type { }; #endif /// is_integral template<typename _Tp> struct is_integral : public integral_constant<bool, (__is_integral_helper<typename remove_cv<_Tp>::type>::value)> { }; template<typename> struct __is_floating_point_helper : public false_type { }; template<> struct __is_floating_point_helper<float> : public true_type { }; template<> struct __is_floating_point_helper<double> : public true_type { }; template<> struct __is_floating_point_helper<long double> : public true_type { }; #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128) template<> struct __is_floating_point_helper<__float128> : public true_type { }; #endif /// is_floating_point template<typename _Tp> struct is_floating_point : public integral_constant<bool, (__is_floating_point_helper<typename remove_cv<_Tp>::type>::value)> { }; /// is_array template<typename> struct is_array : public false_type { }; template<typename _Tp, std::size_t _Size> struct is_array<_Tp[_Size]> : public true_type { }; template<typename _Tp> struct is_array<_Tp[]> : public true_type { }; template<typename> struct __is_pointer_helper : public false_type { }; template<typename _Tp> struct __is_pointer_helper<_Tp*> : public true_type { }; /// is_pointer template<typename _Tp> struct is_pointer : public integral_constant<bool, (__is_pointer_helper<typename remove_cv<_Tp>::type>::value)> { }; /// 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 { }; template<typename> struct is_function; template<typename> struct __is_member_object_pointer_helper : public false_type { }; template<typename _Tp, typename _Cp> struct __is_member_object_pointer_helper<_Tp _Cp::*> : public integral_constant<bool, !is_function<_Tp>::value> { }; /// is_member_object_pointer template<typename _Tp> struct is_member_object_pointer : public integral_constant<bool, (__is_member_object_pointer_helper< typename remove_cv<_Tp>::type>::value)> { }; template<typename> struct __is_member_function_pointer_helper : public false_type { }; template<typename _Tp, typename _Cp> struct __is_member_function_pointer_helper<_Tp _Cp::*> : public integral_constant<bool, is_function<_Tp>::value> { }; /// is_member_function_pointer template<typename _Tp> struct is_member_function_pointer : public integral_constant<bool, (__is_member_function_pointer_helper< typename remove_cv<_Tp>::type>::value)> { }; /// is_enum template<typename _Tp> struct is_enum : public integral_constant<bool, __is_enum(_Tp)> { }; /// is_union template<typename _Tp> struct is_union : public integral_constant<bool, __is_union(_Tp)> { }; /// is_class template<typename _Tp> struct is_class : public integral_constant<bool, __is_class(_Tp)> { }; /// is_function template<typename> struct is_function : public false_type { }; template<typename _Res, typename... _ArgTypes> struct is_function<_Res(_ArgTypes...)> : public true_type { }; template<typename _Res, typename... _ArgTypes> struct is_function<_Res(_ArgTypes......)> : public true_type { }; template<typename _Res, typename... _ArgTypes> struct is_function<_Res(_ArgTypes...) const> : public true_type { }; template<typename _Res, typename... _ArgTypes> struct is_function<_Res(_ArgTypes......) const> : public true_type { }; template<typename _Res, typename... _ArgTypes> struct is_function<_Res(_ArgTypes...) volatile> : public true_type { }; template<typename _Res, typename... _ArgTypes> struct is_function<_Res(_ArgTypes......) volatile> : public true_type { }; template<typename _Res, typename... _ArgTypes> struct is_function<_Res(_ArgTypes...) const volatile> : public true_type { }; template<typename _Res, typename... _ArgTypes> struct is_function<_Res(_ArgTypes......) const volatile> : public true_type { }; template<typename> struct __is_nullptr_t_helper : public false_type { }; template<> struct __is_nullptr_t_helper<std::nullptr_t> : public true_type { }; // __is_nullptr_t (extension). template<typename _Tp> struct __is_nullptr_t : public integral_constant<bool, (__is_nullptr_t_helper<typename remove_cv<_Tp>::type>::value)> { }; // Composite type categories. /// is_reference template<typename _Tp> struct is_reference : public __or_<is_lvalue_reference<_Tp>, is_rvalue_reference<_Tp>>::type { }; /// is_arithmetic template<typename _Tp> struct is_arithmetic : public __or_<is_integral<_Tp>, is_floating_point<_Tp>>::type { }; /// is_fundamental template<typename _Tp> struct is_fundamental : public __or_<is_arithmetic<_Tp>, is_void<_Tp>, __is_nullptr_t<_Tp>>::type { }; /// is_object template<typename _Tp> struct is_object : public __not_<__or_<is_function<_Tp>, is_reference<_Tp>, is_void<_Tp>>>::type { }; template<typename> struct is_member_pointer; /// is_scalar template<typename _Tp> struct is_scalar : public __or_<is_arithmetic<_Tp>, is_enum<_Tp>, is_pointer<_Tp>, is_member_pointer<_Tp>, __is_nullptr_t<_Tp>>::type { }; /// is_compound template<typename _Tp> struct is_compound : public integral_constant<bool, !is_fundamental<_Tp>::value> { }; template<typename _Tp> struct __is_member_pointer_helper : public false_type { }; template<typename _Tp, typename _Cp> struct __is_member_pointer_helper<_Tp _Cp::*> : public true_type { }; /// is_member_pointer template<typename _Tp> struct is_member_pointer : public integral_constant<bool, (__is_member_pointer_helper< typename remove_cv<_Tp>::type>::value)> { }; // Type properties. /// is_const template<typename> struct is_const : public false_type { }; template<typename _Tp> struct is_const<_Tp const> : public true_type { }; /// is_volatile template<typename> struct is_volatile : public false_type { }; template<typename _Tp> struct is_volatile<_Tp volatile> : public true_type { }; /// is_trivial template<typename _Tp> struct is_trivial : public integral_constant<bool, __is_trivial(_Tp)> { }; // is_trivially_copyable (still unimplemented) /// 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)> { }; /// is_literal_type template<typename _Tp> struct is_literal_type : public integral_constant<bool, __is_literal_type(_Tp)> { }; /// is_empty template<typename _Tp> struct is_empty : public integral_constant<bool, __is_empty(_Tp)> { }; /// is_polymorphic template<typename _Tp> struct is_polymorphic : public integral_constant<bool, __is_polymorphic(_Tp)> { }; /// is_abstract template<typename _Tp> struct is_abstract : public integral_constant<bool, __is_abstract(_Tp)> { }; 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 __and_<is_arithmetic<_Tp>, __not_<is_signed<_Tp>>>::type { }; // Destructible and constructible type properties. template<typename> struct add_rvalue_reference; /** * @brief Utility to simplify expressions used in unevaluated operands * @ingroup utilities */ template<typename _Tp> typename add_rvalue_reference<_Tp>::type declval() noexcept; template<typename, unsigned = 0> struct extent; template<typename> struct remove_all_extents; template<typename _Tp> struct __is_array_known_bounds : public integral_constant<bool, (extent<_Tp>::value > 0)> { }; template<typename _Tp> struct __is_array_unknown_bounds : public __and_<is_array<_Tp>, __not_<extent<_Tp>>>::type { }; // In N3290 is_destructible does not say anything about function // types and abstract types, see LWG 2049. This implementation // describes function types as non-destructible and all complete // object types as destructible, iff the explicit destructor // call expression is wellformed. struct __do_is_destructible_impl { template<typename _Tp, typename = decltype(declval<_Tp&>().~_Tp())> static true_type __test(int); template<typename> static false_type __test(...); }; template<typename _Tp> struct __is_destructible_impl : public __do_is_destructible_impl { typedef decltype(__test<_Tp>(0)) type; }; template<typename _Tp, bool = __or_<is_void<_Tp>, __is_array_unknown_bounds<_Tp>, is_function<_Tp>>::value, bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value> struct __is_destructible_safe; template<typename _Tp> struct __is_destructible_safe<_Tp, false, false> : public __is_destructible_impl<typename remove_all_extents<_Tp>::type>::type { }; template<typename _Tp> struct __is_destructible_safe<_Tp, true, false> : public false_type { }; template<typename _Tp> struct __is_destructible_safe<_Tp, false, true> : public true_type { }; /// is_destructible template<typename _Tp> struct is_destructible : public integral_constant<bool, (__is_destructible_safe<_Tp>::value)> { }; // is_nothrow_destructible requires that is_destructible is // satisfied as well. We realize that by mimicing the // implementation of is_destructible but refer to noexcept(expr) // instead of decltype(expr). struct __do_is_nt_destructible_impl { template<typename _Tp> static integral_constant<bool, noexcept(declval<_Tp&>().~_Tp())> __test(int); template<typename> static false_type __test(...); }; template<typename _Tp> struct __is_nt_destructible_impl : public __do_is_nt_destructible_impl { typedef decltype(__test<_Tp>(0)) type; }; template<typename _Tp, bool = __or_<is_void<_Tp>, __is_array_unknown_bounds<_Tp>, is_function<_Tp>>::value, bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value> struct __is_nt_destructible_safe; template<typename _Tp> struct __is_nt_destructible_safe<_Tp, false, false> : public __is_nt_destructible_impl<typename remove_all_extents<_Tp>::type>::type { }; template<typename _Tp> struct __is_nt_destructible_safe<_Tp, true, false> : public false_type { }; template<typename _Tp> struct __is_nt_destructible_safe<_Tp, false, true> : public true_type { }; /// is_nothrow_destructible template<typename _Tp> struct is_nothrow_destructible : public integral_constant<bool, (__is_nt_destructible_safe<_Tp>::value)> { }; struct __do_is_default_constructible_impl { template<typename _Tp, typename = decltype(_Tp())> static true_type __test(int); template<typename> static false_type __test(...); }; template<typename _Tp> struct __is_default_constructible_impl : public __do_is_default_constructible_impl { typedef decltype(__test<_Tp>(0)) type; }; template<typename _Tp> struct __is_default_constructible_atom : public __and_<__not_<is_void<_Tp>>, __is_default_constructible_impl<_Tp>>::type { }; template<typename _Tp, bool = is_array<_Tp>::value> struct __is_default_constructible_safe; // The following technique is a workaround for a current core language // restriction, which does not allow for array types to occur in // functional casts of the form T(). Complete arrays can be default- // constructed, if the element type is default-constructible, but // arrays with unknown bounds are not. template<typename _Tp> struct __is_default_constructible_safe<_Tp, true> : public __and_<__is_array_known_bounds<_Tp>, __is_default_constructible_atom<typename remove_all_extents<_Tp>::type>>::type { }; template<typename _Tp> struct __is_default_constructible_safe<_Tp, false> : public __is_default_constructible_atom<_Tp>::type { }; /// is_default_constructible template<typename _Tp> struct is_default_constructible : public integral_constant<bool, (__is_default_constructible_safe< _Tp>::value)> { }; // Implementation of is_constructible. // The hardest part of this trait is the binary direct-initialization // case, because we hit into a functional cast of the form T(arg). // This implementation uses different strategies depending on the // target type to reduce the test overhead as much as possible: // // a) For a reference target type, we use a static_cast expression // modulo its extra cases. // // b) For a non-reference target type we use a ::new expression. struct __do_is_static_castable_impl { template<typename _From, typename _To, typename = decltype(static_cast<_To>(declval<_From>()))> static true_type __test(int); template<typename, typename> static false_type __test(...); }; template<typename _From, typename _To> struct __is_static_castable_impl : public __do_is_static_castable_impl { typedef decltype(__test<_From, _To>(0)) type; }; template<typename _From, typename _To> struct __is_static_castable_safe : public __is_static_castable_impl<_From, _To>::type { }; // __is_static_castable template<typename _From, typename _To> struct __is_static_castable : public integral_constant<bool, (__is_static_castable_safe< _From, _To>::value)> { }; // Implementation for non-reference types. To meet the proper // variable definition semantics, we also need to test for // is_destructible in this case. // This form should be simplified by a single expression: // ::delete ::new _Tp(declval<_Arg>()), see c++/51222. struct __do_is_direct_constructible_impl { template<typename _Tp, typename _Arg, typename = decltype(::new _Tp(declval<_Arg>()))> static true_type __test(int); template<typename, typename> static false_type __test(...); }; template<typename _Tp, typename _Arg> struct __is_direct_constructible_impl : public __do_is_direct_constructible_impl { typedef decltype(__test<_Tp, _Arg>(0)) type; }; template<typename _Tp, typename _Arg> struct __is_direct_constructible_new_safe : public __and_<is_destructible<_Tp>, __is_direct_constructible_impl<_Tp, _Arg>>::type { }; template<typename, typename> struct is_same; template<typename, typename> struct is_base_of; template<typename> struct remove_reference; template<typename _From, typename _To, bool = __not_<__or_<is_void<_From>, is_function<_From>>>::value> struct __is_base_to_derived_ref; // Detect whether we have a downcast situation during // reference binding. template<typename _From, typename _To> struct __is_base_to_derived_ref<_From, _To, true> { typedef typename remove_cv<typename remove_reference<_From >::type>::type __src_t; typedef typename remove_cv<typename remove_reference<_To >::type>::type __dst_t; typedef __and_<__not_<is_same<__src_t, __dst_t>>, is_base_of<__src_t, __dst_t>> type; static constexpr bool value = type::value; }; template<typename _From, typename _To> struct __is_base_to_derived_ref<_From, _To, false> : public false_type { }; template<typename _From, typename _To, bool = __and_<is_lvalue_reference<_From>, is_rvalue_reference<_To>>::value> struct __is_lvalue_to_rvalue_ref; // Detect whether we have an lvalue of non-function type // bound to a reference-compatible rvalue-reference. template<typename _From, typename _To> struct __is_lvalue_to_rvalue_ref<_From, _To, true> { typedef typename remove_cv<typename remove_reference< _From>::type>::type __src_t; typedef typename remove_cv<typename remove_reference< _To>::type>::type __dst_t; typedef __and_<__not_<is_function<__src_t>>, __or_<is_same<__src_t, __dst_t>, is_base_of<__dst_t, __src_t>>> type; static constexpr bool value = type::value; }; template<typename _From, typename _To> struct __is_lvalue_to_rvalue_ref<_From, _To, false> : public false_type { }; // Here we handle direct-initialization to a reference type as // equivalent to a static_cast modulo overshooting conversions. // These are restricted to the following conversions: // a) A base class value to a derived class reference // b) An lvalue to an rvalue-reference of reference-compatible // types that are not functions template<typename _Tp, typename _Arg> struct __is_direct_constructible_ref_cast : public __and_<__is_static_castable<_Arg, _Tp>, __not_<__or_<__is_base_to_derived_ref<_Arg, _Tp>, __is_lvalue_to_rvalue_ref<_Arg, _Tp> >>>::type { }; template<typename _Tp, typename _Arg> struct __is_direct_constructible_new : public conditional<is_reference<_Tp>::value, __is_direct_constructible_ref_cast<_Tp, _Arg>, __is_direct_constructible_new_safe<_Tp, _Arg> >::type { }; template<typename _Tp, typename _Arg> struct __is_direct_constructible : public integral_constant<bool, (__is_direct_constructible_new< _Tp, _Arg>::value)> { }; // Since default-construction and binary direct-initialization have // been handled separately, the implementation of the remaining // n-ary construction cases is rather straightforward. We can use // here a functional cast, because array types are excluded anyway // and this form is never interpreted as a C cast. struct __do_is_nary_constructible_impl { template<typename _Tp, typename... _Args, typename = decltype(_Tp(declval<_Args>()...))> static true_type __test(int); template<typename, typename...> static false_type __test(...); }; template<typename _Tp, typename... _Args> struct __is_nary_constructible_impl : public __do_is_nary_constructible_impl { typedef decltype(__test<_Tp, _Args...>(0)) type; }; template<typename _Tp, typename... _Args> struct __is_nary_constructible : public __is_nary_constructible_impl<_Tp, _Args...>::type { static_assert(sizeof...(_Args) > 1, "Only useful for > 1 arguments"); }; template<typename _Tp, typename... _Args> struct __is_constructible_impl : public __is_nary_constructible<_Tp, _Args...> { }; template<typename _Tp, typename _Arg> struct __is_constructible_impl<_Tp, _Arg> : public __is_direct_constructible<_Tp, _Arg> { }; template<typename _Tp> struct __is_constructible_impl<_Tp> : public is_default_constructible<_Tp> { }; /// is_constructible template<typename _Tp, typename... _Args> struct is_constructible : public integral_constant<bool, (__is_constructible_impl<_Tp, _Args...>::value)> { }; template<typename _Tp, bool = is_void<_Tp>::value> struct __is_copy_constructible_impl; template<typename _Tp> struct __is_copy_constructible_impl<_Tp, true> : public false_type { }; template<typename _Tp> struct __is_copy_constructible_impl<_Tp, false> : public is_constructible<_Tp, const _Tp&> { }; /// is_copy_constructible template<typename _Tp> struct is_copy_constructible : public __is_copy_constructible_impl<_Tp> { }; template<typename _Tp, bool = is_void<_Tp>::value> struct __is_move_constructible_impl; template<typename _Tp> struct __is_move_constructible_impl<_Tp, true> : public false_type { }; template<typename _Tp> struct __is_move_constructible_impl<_Tp, false> : public is_constructible<_Tp, _Tp&&> { }; /// is_move_constructible template<typename _Tp> struct is_move_constructible : public __is_move_constructible_impl<_Tp> { }; template<typename _Tp> struct __is_nt_default_constructible_atom : public integral_constant<bool, noexcept(_Tp())> { }; template<typename _Tp, bool = is_array<_Tp>::value> struct __is_nt_default_constructible_impl; template<typename _Tp> struct __is_nt_default_constructible_impl<_Tp, true> : public __and_<__is_array_known_bounds<_Tp>, __is_nt_default_constructible_atom<typename remove_all_extents<_Tp>::type>>::type { }; template<typename _Tp> struct __is_nt_default_constructible_impl<_Tp, false> : public __is_nt_default_constructible_atom<_Tp> { }; /// is_nothrow_default_constructible template<typename _Tp> struct is_nothrow_default_constructible : public __and_<is_default_constructible<_Tp>, __is_nt_default_constructible_impl<_Tp>>::type { }; template<typename _Tp, typename... _Args> struct __is_nt_constructible_impl : public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))> { }; template<typename _Tp, typename _Arg> struct __is_nt_constructible_impl<_Tp, _Arg> : public integral_constant<bool, noexcept(static_cast<_Tp>(declval<_Arg>()))> { }; template<typename _Tp> struct __is_nt_constructible_impl<_Tp> : public is_nothrow_default_constructible<_Tp> { }; /// is_nothrow_constructible template<typename _Tp, typename... _Args> struct is_nothrow_constructible : public __and_<is_constructible<_Tp, _Args...>, __is_nt_constructible_impl<_Tp, _Args...>>::type { }; template<typename _Tp, bool = is_void<_Tp>::value> struct __is_nothrow_copy_constructible_impl; template<typename _Tp> struct __is_nothrow_copy_constructible_impl<_Tp, true> : public false_type { }; template<typename _Tp> struct __is_nothrow_copy_constructible_impl<_Tp, false> : public is_nothrow_constructible<_Tp, const _Tp&> { }; /// is_nothrow_copy_constructible template<typename _Tp> struct is_nothrow_copy_constructible : public __is_nothrow_copy_constructible_impl<_Tp> { }; template<typename _Tp, bool = is_void<_Tp>::value> struct __is_nothrow_move_constructible_impl; template<typename _Tp> struct __is_nothrow_move_constructible_impl<_Tp, true> : public false_type { }; template<typename _Tp> struct __is_nothrow_move_constructible_impl<_Tp, false> : public is_nothrow_constructible<_Tp, _Tp&&> { }; /// is_nothrow_move_constructible template<typename _Tp> struct is_nothrow_move_constructible : public __is_nothrow_move_constructible_impl<_Tp> { }; template<typename _Tp, typename _Up> class __is_assignable_helper : public __sfinae_types { template<typename _Tp1, typename _Up1> static decltype(declval<_Tp1>() = declval<_Up1>(), __one()) __test(int); template<typename, typename> static __two __test(...); public: static constexpr bool value = sizeof(__test<_Tp, _Up>(0)) == 1; }; /// is_assignable template<typename _Tp, typename _Up> struct is_assignable : public integral_constant<bool, __is_assignable_helper<_Tp, _Up>::value> { }; template<typename _Tp, bool = is_void<_Tp>::value> struct __is_copy_assignable_impl; template<typename _Tp> struct __is_copy_assignable_impl<_Tp, true> : public false_type { }; template<typename _Tp> struct __is_copy_assignable_impl<_Tp, false> : public is_assignable<_Tp&, const _Tp&> { }; /// is_copy_assignable template<typename _Tp> struct is_copy_assignable : public __is_copy_assignable_impl<_Tp> { }; template<typename _Tp, bool = is_void<_Tp>::value> struct __is_move_assignable_impl; template<typename _Tp> struct __is_move_assignable_impl<_Tp, true> : public false_type { }; template<typename _Tp> struct __is_move_assignable_impl<_Tp, false> : public is_assignable<_Tp&, _Tp&&> { }; /// is_move_assignable template<typename _Tp> struct is_move_assignable : public __is_move_assignable_impl<_Tp> { }; template<typename _Tp, typename _Up> struct __is_nt_assignable_impl : public integral_constant<bool, noexcept(declval<_Tp>() = declval<_Up>())> { }; /// is_nothrow_assignable template<typename _Tp, typename _Up> struct is_nothrow_assignable : public __and_<is_assignable<_Tp, _Up>, __is_nt_assignable_impl<_Tp, _Up>>::type { }; template<typename _Tp, bool = is_void<_Tp>::value> struct __is_nt_copy_assignable_impl; template<typename _Tp> struct __is_nt_copy_assignable_impl<_Tp, true> : public false_type { }; template<typename _Tp> struct __is_nt_copy_assignable_impl<_Tp, false> : public is_nothrow_assignable<_Tp&, const _Tp&> { }; /// is_nothrow_copy_assignable template<typename _Tp> struct is_nothrow_copy_assignable : public __is_nt_copy_assignable_impl<_Tp> { }; template<typename _Tp, bool = is_void<_Tp>::value> struct __is_nt_move_assignable_impl; template<typename _Tp> struct __is_nt_move_assignable_impl<_Tp, true> : public false_type { }; template<typename _Tp> struct __is_nt_move_assignable_impl<_Tp, false> : public is_nothrow_assignable<_Tp&, _Tp&&> { }; /// is_nothrow_move_assignable template<typename _Tp> struct is_nothrow_move_assignable : public __is_nt_move_assignable_impl<_Tp> { }; /// is_trivially_constructible (still unimplemented) /// is_trivially_default_constructible (still unimplemented) /// is_trivially_copy_constructible (still unimplemented) /// is_trivially_move_constructible (still unimplemented) /// is_trivially_assignable (still unimplemented) /// is_trivially_copy_assignable (still unimplemented) /// is_trivially_move_assignable (still unimplemented) /// is_trivially_destructible template<typename _Tp> struct is_trivially_destructible : public __and_<is_destructible<_Tp>, integral_constant<bool, __has_trivial_destructor(_Tp)>>::type { }; /// has_trivial_default_constructor (temporary legacy) template<typename _Tp> struct has_trivial_default_constructor : public integral_constant<bool, __has_trivial_constructor(_Tp)> { }; /// has_trivial_copy_constructor (temporary legacy) template<typename _Tp> struct has_trivial_copy_constructor : public integral_constant<bool, __has_trivial_copy(_Tp)> { }; /// has_trivial_copy_assign (temporary legacy) template<typename _Tp> struct has_trivial_copy_assign : public integral_constant<bool, __has_trivial_assign(_Tp)> { }; /// has_virtual_destructor template<typename _Tp> struct has_virtual_destructor : public integral_constant<bool, __has_virtual_destructor(_Tp)> { }; // type property queries. /// alignment_of template<typename _Tp> struct alignment_of : public integral_constant<std::size_t, __alignof__(_Tp)> { }; /// rank template<typename> struct rank : public integral_constant<std::size_t, 0> { }; template<typename _Tp, std::size_t _Size> struct rank<_Tp[_Size]> : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { }; template<typename _Tp> struct rank<_Tp[]> : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { }; /// extent template<typename, unsigned _Uint> struct extent : public integral_constant<std::size_t, 0> { }; template<typename _Tp, unsigned _Uint, std::size_t _Size> struct extent<_Tp[_Size], _Uint> : public integral_constant<std::size_t, _Uint == 0 ? _Size : extent<_Tp, _Uint - 1>::value> { }; template<typename _Tp, unsigned _Uint> struct extent<_Tp[], _Uint> : public integral_constant<std::size_t, _Uint == 0 ? 0 : extent<_Tp, _Uint - 1>::value> { }; // Type relations. /// is_same template<typename, typename> struct is_same : public false_type { }; template<typename _Tp> struct is_same<_Tp, _Tp> : public true_type { }; /// 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 = __or_<is_void<_From>, is_function<_To>, is_array<_To>>::value> struct __is_convertible_helper { static constexpr 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 constexpr bool value = sizeof(__test<_From, _To>(0)) == 1; }; /// is_convertible template<typename _From, typename _To> struct is_convertible : public integral_constant<bool, __is_convertible_helper<_From, _To>::value> { }; // Const-volatile modifications. /// remove_const template<typename _Tp> struct remove_const { typedef _Tp type; }; template<typename _Tp> struct remove_const<_Tp const> { typedef _Tp type; }; /// remove_volatile template<typename _Tp> struct remove_volatile { typedef _Tp type; }; template<typename _Tp> struct remove_volatile<_Tp volatile> { typedef _Tp type; }; /// remove_cv template<typename _Tp> struct remove_cv { typedef typename remove_const<typename remove_volatile<_Tp>::type>::type type; }; /// add_const template<typename _Tp> struct add_const { typedef _Tp const type; }; /// add_volatile template<typename _Tp> struct add_volatile { typedef _Tp volatile type; }; /// add_cv template<typename _Tp> struct add_cv { typedef typename add_const<typename add_volatile<_Tp>::type>::type type; }; // 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 = __and_<__not_<is_reference<_Tp>>, __not_<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 = __and_<__not_<is_reference<_Tp>>, __not_<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> { }; // Sign modifications. // 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; }; #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_INT128) template<> struct __make_unsigned<__int128> { typedef unsigned __int128 __type; }; #endif // 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; }; #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_INT128) template<> struct __make_signed<unsigned __int128> { typedef __int128 __type; }; #endif // 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>; // Array modifications. /// remove_extent template<typename _Tp> struct remove_extent { typedef _Tp type; }; template<typename _Tp, std::size_t _Size> struct remove_extent<_Tp[_Size]> { typedef _Tp type; }; template<typename _Tp> struct remove_extent<_Tp[]> { typedef _Tp type; }; /// remove_all_extents template<typename _Tp> struct remove_all_extents { typedef _Tp type; }; template<typename _Tp, std::size_t _Size> struct remove_all_extents<_Tp[_Size]> { typedef typename remove_all_extents<_Tp>::type type; }; template<typename _Tp> struct remove_all_extents<_Tp[]> { typedef typename remove_all_extents<_Tp>::type type; }; // Pointer modifications. template<typename _Tp, typename> struct __remove_pointer_helper { typedef _Tp type; }; template<typename _Tp, typename _Up> struct __remove_pointer_helper<_Tp, _Up*> { typedef _Up type; }; /// remove_pointer template<typename _Tp> struct remove_pointer : public __remove_pointer_helper<_Tp, typename remove_cv<_Tp>::type> { }; /// add_pointer template<typename _Tp> struct add_pointer { typedef typename remove_reference<_Tp>::type* type; }; 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; }; }; // 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; }; // Primary template. /// Define a member typedef @c type only if a boolean constant is true. template<bool, typename _Tp = void> struct enable_if { }; // Partial specialization for true. template<typename _Tp> struct enable_if<true, _Tp> { typedef _Tp type; }; template<typename... _Cond> using _Require = typename enable_if<__and_<_Cond...>::value>::type; // Primary template. /// Define a member typedef @c type to one of two argument types. 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; }; /// common_type template<typename... _Tp> struct common_type; // Sfinae-friendly common_type implementation: struct __do_common_type_impl { template<typename _Tp, typename _Up> static __success_type<typename decay<decltype (true ? std::declval<_Tp>() : std::declval<_Up>())>::type> _S_test(int); template<typename, typename> static __failure_type _S_test(...); }; template<typename _Tp, typename _Up> struct __common_type_impl : private __do_common_type_impl { typedef decltype(_S_test<_Tp, _Up>(0)) type; }; struct __do_member_type_wrapper { template<typename _Tp> static __success_type<typename _Tp::type> _S_test(int); template<typename> static __failure_type _S_test(...); }; template<typename _Tp> struct __member_type_wrapper : private __do_member_type_wrapper { typedef decltype(_S_test<_Tp>(0)) type; }; template<typename _CTp, typename... _Args> struct __expanded_common_type_wrapper { typedef common_type<typename _CTp::type, _Args...> type; }; template<typename... _Args> struct __expanded_common_type_wrapper<__failure_type, _Args...> { typedef __failure_type type; }; template<typename _Tp> struct common_type<_Tp> { typedef typename decay<_Tp>::type type; }; template<typename _Tp, typename _Up> struct common_type<_Tp, _Up> : public __common_type_impl<_Tp, _Up>::type { }; template<typename _Tp, typename _Up, typename... _Vp> struct common_type<_Tp, _Up, _Vp...> : public __expanded_common_type_wrapper<typename __member_type_wrapper< common_type<_Tp, _Up>>::type, _Vp...>::type { }; /// The underlying type of an enum. template<typename _Tp> struct underlying_type { typedef __underlying_type(_Tp) type; }; 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; // Sfinae-friendly result_of implementation: // [func.require] paragraph 1 bullet 1: struct __result_of_memfun_ref_impl { template<typename _Fp, typename _Tp1, typename... _Args> static __success_type<decltype( (std::declval<_Tp1>().*std::declval<_Fp>())(std::declval<_Args>()...) )> _S_test(int); template<typename...> static __failure_type _S_test(...); }; template<typename _MemPtr, typename _Arg, typename... _Args> struct __result_of_memfun_ref : private __result_of_memfun_ref_impl { typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type; }; // [func.require] paragraph 1 bullet 2: struct __result_of_memfun_deref_impl { template<typename _Fp, typename _Tp1, typename... _Args> static __success_type<decltype( ((*std::declval<_Tp1>()).*std::declval<_Fp>())(std::declval<_Args>()...) )> _S_test(int); template<typename...> static __failure_type _S_test(...); }; template<typename _MemPtr, typename _Arg, typename... _Args> struct __result_of_memfun_deref : private __result_of_memfun_deref_impl { typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type; }; // [func.require] paragraph 1 bullet 3: struct __result_of_memobj_ref_impl { template<typename _Fp, typename _Tp1> static __success_type<decltype( std::declval<_Tp1>().*std::declval<_Fp>() )> _S_test(int); template<typename, typename> static __failure_type _S_test(...); }; template<typename _MemPtr, typename _Arg> struct __result_of_memobj_ref : private __result_of_memobj_ref_impl { typedef decltype(_S_test<_MemPtr, _Arg>(0)) type; }; // [func.require] paragraph 1 bullet 4: struct __result_of_memobj_deref_impl { template<typename _Fp, typename _Tp1> static __success_type<decltype( (*std::declval<_Tp1>()).*std::declval<_Fp>() )> _S_test(int); template<typename, typename> static __failure_type _S_test(...); }; template<typename _MemPtr, typename _Arg> struct __result_of_memobj_deref : private __result_of_memobj_deref_impl { typedef decltype(_S_test<_MemPtr, _Arg>(0)) type; }; template<typename _MemPtr, typename _Arg> struct __result_of_memobj; template<typename _Res, typename _Class, typename _Arg> struct __result_of_memobj<_Res _Class::*, _Arg> { typedef typename remove_cv<typename remove_reference< _Arg>::type>::type _Argval; typedef _Res _Class::* _MemPtr; typedef typename conditional<__or_<is_same<_Argval, _Class>, is_base_of<_Class, _Argval>>::value, __result_of_memobj_ref<_MemPtr, _Arg>, __result_of_memobj_deref<_MemPtr, _Arg> >::type::type type; }; template<typename _MemPtr, typename _Arg, typename... _Args> struct __result_of_memfun; template<typename _Res, typename _Class, typename _Arg, typename... _Args> struct __result_of_memfun<_Res _Class::*, _Arg, _Args...> { typedef typename remove_cv<typename remove_reference< _Arg>::type>::type _Argval; typedef _Res _Class::* _MemPtr; typedef typename conditional<__or_<is_same<_Argval, _Class>, is_base_of<_Class, _Argval>>::value, __result_of_memfun_ref<_MemPtr, _Arg, _Args...>, __result_of_memfun_deref<_MemPtr, _Arg, _Args...> >::type::type type; }; template<bool, bool, typename _Functor, typename... _ArgTypes> struct __result_of_impl { typedef __failure_type type; }; template<typename _MemPtr, typename _Arg> struct __result_of_impl<true, false, _MemPtr, _Arg> : public __result_of_memobj<typename decay<_MemPtr>::type, _Arg> { }; template<typename _MemPtr, typename _Arg, typename... _Args> struct __result_of_impl<false, true, _MemPtr, _Arg, _Args...> : public __result_of_memfun<typename decay<_MemPtr>::type, _Arg, _Args...> { }; // [func.require] paragraph 1 bullet 5: struct __result_of_other_impl { template<typename _Fn, typename... _Args> static __success_type<decltype( std::declval<_Fn>()(std::declval<_Args>()...) )> _S_test(int); template<typename...> static __failure_type _S_test(...); }; template<typename _Functor, typename... _ArgTypes> struct __result_of_impl<false, false, _Functor, _ArgTypes...> : private __result_of_other_impl { typedef decltype(_S_test<_Functor, _ArgTypes...>(0)) type; }; template<typename _Functor, typename... _ArgTypes> struct result_of<_Functor(_ArgTypes...)> : public __result_of_impl< is_member_object_pointer< typename remove_reference<_Functor>::type >::value, is_member_function_pointer< typename remove_reference<_Functor>::type >::value, _Functor, _ArgTypes... >::type { }; /// @} group metaprogramming /** * Use SFINAE to determine if the type _Tp has a publicly-accessible * member type _NTYPE. */ #define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE) \ template<typename _Tp> \ class __has_##_NTYPE##_helper \ : __sfinae_types \ { \ template<typename _Up> \ struct _Wrap_type \ { }; \ \ template<typename _Up> \ static __one __test(_Wrap_type<typename _Up::_NTYPE>*); \ \ template<typename _Up> \ static __two __test(...); \ \ public: \ static constexpr bool value = sizeof(__test<_Tp>(0)) == 1; \ }; \ \ template<typename _Tp> \ struct __has_##_NTYPE \ : integral_constant<bool, __has_##_NTYPE##_helper \ <typename remove_cv<_Tp>::type>::value> \ { }; _GLIBCXX_END_NAMESPACE_VERSION } // namespace std #endif // C++11 #endif // _GLIBCXX_TYPE_TRAITS