type_traits
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// C++11 <type_traits> -*- C++ -*-
// Copyright (C) 2007-2026 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
#ifdef _GLIBCXX_SYSHDR
#pragma GCC system_header
#endif
#if __cplusplus < 201103L
# include <bits/c++0x_warning.h>
#else
#include <bits/c++config.h>
#define __glibcxx_want_bool_constant
#define __glibcxx_want_bounded_array_traits
#define __glibcxx_want_common_reference
#define __glibcxx_want_has_unique_object_representations
#define __glibcxx_want_integral_constant_callable
#define __glibcxx_want_is_aggregate
#define __glibcxx_want_is_constant_evaluated
#define __glibcxx_want_is_final
#define __glibcxx_want_is_implicit_lifetime
#define __glibcxx_want_is_invocable
#define __glibcxx_want_is_layout_compatible
#define __glibcxx_want_is_nothrow_convertible
#define __glibcxx_want_is_null_pointer
#define __glibcxx_want_is_pointer_interconvertible
#define __glibcxx_want_is_scoped_enum
#define __glibcxx_want_is_structural
#define __glibcxx_want_is_swappable
#define __glibcxx_want_is_virtual_base_of
#define __glibcxx_want_logical_traits
#define __glibcxx_want_reference_from_temporary
#define __glibcxx_want_remove_cvref
#define __glibcxx_want_result_of_sfinae
#define __glibcxx_want_transformation_trait_aliases
#define __glibcxx_want_type_identity
#define __glibcxx_want_type_trait_variable_templates
#define __glibcxx_want_unwrap_ref
#define __glibcxx_want_void_t
#include <bits/version.h>
extern "C++"
{
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp>
class reference_wrapper;
/**
* @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.
*
* @since C++11
*
* @{
*/
/// integral_constant
template<typename _Tp, _Tp __v>
struct integral_constant
{
static constexpr _Tp value = __v;
using value_type = _Tp;
using type = integral_constant<_Tp, __v>;
constexpr operator value_type() const noexcept { return value; }
#ifdef __cpp_lib_integral_constant_callable // C++ >= 14
constexpr value_type operator()() const noexcept { return value; }
#endif
};
#if ! __cpp_inline_variables
template<typename _Tp, _Tp __v>
constexpr _Tp integral_constant<_Tp, __v>::value;
#endif
/// @cond undocumented
/// bool_constant for C++11
template<bool __v>
using __bool_constant = integral_constant<bool, __v>;
/// @endcond
/// The type used as a compile-time boolean with true value.
using true_type = __bool_constant<true>;
/// The type used as a compile-time boolean with false value.
using false_type = __bool_constant<false>;
#ifdef __cpp_lib_bool_constant // C++ >= 17
/// Alias template for compile-time boolean constant types.
/// @since C++17
template<bool __v>
using bool_constant = __bool_constant<__v>;
#endif
// Metaprogramming helper types.
// Primary template.
/// Define a member typedef `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>
{ using type = _Tp; };
// __enable_if_t (std::enable_if_t for C++11)
template<bool _Cond, typename _Tp = void>
using __enable_if_t = typename enable_if<_Cond, _Tp>::type;
template<bool>
struct __conditional
{
template<typename _Tp, typename>
using type = _Tp;
};
template<>
struct __conditional<false>
{
template<typename, typename _Up>
using type = _Up;
};
// More efficient version of std::conditional_t for internal use (and C++11)
template<bool _Cond, typename _If, typename _Else>
using __conditional_t
= typename __conditional<_Cond>::template type<_If, _Else>;
/// @cond undocumented
template <typename _Type>
struct __type_identity
{ using type = _Type; };
template<typename _Tp>
using __type_identity_t = typename __type_identity<_Tp>::type;
namespace __detail
{
// A variadic alias template that resolves to its first argument.
template<typename _Tp, typename...>
using __first_t = _Tp;
// These are deliberately not defined.
template<typename... _Bn>
auto __or_fn(int) -> __first_t<false_type,
__enable_if_t<!bool(_Bn::value)>...>;
template<typename... _Bn>
auto __or_fn(...) -> true_type;
template<typename... _Bn>
auto __and_fn(int) -> __first_t<true_type,
__enable_if_t<bool(_Bn::value)>...>;
template<typename... _Bn>
auto __and_fn(...) -> false_type;
} // namespace detail
// Like C++17 std::dis/conjunction, but usable in C++11 and resolves
// to either true_type or false_type which allows for a more efficient
// implementation that avoids recursive class template instantiation.
template<typename... _Bn>
struct __or_
: decltype(__detail::__or_fn<_Bn...>(0))
{ };
template<typename... _Bn>
struct __and_
: decltype(__detail::__and_fn<_Bn...>(0))
{ };
template<typename _Pp>
struct __not_
: __bool_constant<!bool(_Pp::value)>
{ };
/// @endcond
#ifdef __cpp_lib_logical_traits // C++ >= 17
/// @cond undocumented
template<typename... _Bn>
inline constexpr bool __or_v = __or_<_Bn...>::value;
template<typename... _Bn>
inline constexpr bool __and_v = __and_<_Bn...>::value;
namespace __detail
{
template<typename /* = void */, typename _B1, typename... _Bn>
struct __disjunction_impl
{ using type = _B1; };
template<typename _B1, typename _B2, typename... _Bn>
struct __disjunction_impl<__enable_if_t<!bool(_B1::value)>, _B1, _B2, _Bn...>
{ using type = typename __disjunction_impl<void, _B2, _Bn...>::type; };
template<typename /* = void */, typename _B1, typename... _Bn>
struct __conjunction_impl
{ using type = _B1; };
template<typename _B1, typename _B2, typename... _Bn>
struct __conjunction_impl<__enable_if_t<bool(_B1::value)>, _B1, _B2, _Bn...>
{ using type = typename __conjunction_impl<void, _B2, _Bn...>::type; };
} // namespace __detail
/// @endcond
template<typename... _Bn>
struct conjunction
: __detail::__conjunction_impl<void, _Bn...>::type
{ };
template<>
struct conjunction<>
: true_type
{ };
template<typename... _Bn>
struct disjunction
: __detail::__disjunction_impl<void, _Bn...>::type
{ };
template<>
struct disjunction<>
: false_type
{ };
template<typename _Pp>
struct negation
: __not_<_Pp>::type
{ };
/** @ingroup variable_templates
* @{
*/
template<typename... _Bn>
inline constexpr bool conjunction_v = conjunction<_Bn...>::value;
template<typename... _Bn>
inline constexpr bool disjunction_v = disjunction<_Bn...>::value;
template<typename _Pp>
inline constexpr bool negation_v = negation<_Pp>::value;
/// @}
#endif // __cpp_lib_logical_traits
// Forward declarations
template<typename>
struct is_object;
template<typename>
struct remove_cv;
template<typename>
struct is_const;
/// @cond undocumented
template<typename>
struct __is_array_unknown_bounds;
// An object type which is not an unbounded array.
// It might still be an incomplete type, but if this is false_type
// then we can be certain it's not a complete object type.
template<typename _Tp>
using __maybe_complete_object_type
= __and_<is_object<_Tp>, __not_<__is_array_unknown_bounds<_Tp>>>;
// Helper functions that return false_type for incomplete classes,
// incomplete unions and arrays of known bound from those.
// More specialized overload for complete object types (returning true_type).
template<typename _Tp,
typename = __enable_if_t<__maybe_complete_object_type<_Tp>::value>,
size_t = sizeof(_Tp)>
constexpr true_type
__is_complete_or_unbounded(__type_identity<_Tp>)
{ return {}; };
// Less specialized overload for reference and unknown-bound array types
// (returning true_type), and incomplete types (returning false_type).
template<typename _TypeIdentity,
typename _NestedType = typename _TypeIdentity::type>
constexpr typename __not_<__maybe_complete_object_type<_NestedType>>::type
__is_complete_or_unbounded(_TypeIdentity)
{ return {}; }
// __remove_cv_t (std::remove_cv_t for C++11).
template<typename _Tp>
using __remove_cv_t = typename remove_cv<_Tp>::type;
/// @endcond
// Primary type categories.
/// is_void
template<typename _Tp>
struct is_void
: public false_type { };
template<>
struct is_void<void>
: public true_type { };
template<>
struct is_void<const void>
: public true_type { };
template<>
struct is_void<volatile void>
: public true_type { };
template<>
struct is_void<const volatile void>
: public true_type { };
/// @cond undocumented
// Every integral type is either one of the character types, one of the
// signed integer types, one of the unsigned integer types, or bool,
// or a cv-qualified version of one of those types ([basic.fundamental]).
// For now we only need to distinguish the signed/unsigned integer types.
enum class _Integer_kind { _None, _Signed, _Unsigned };
template<typename>
struct __is_integral_helper
: public false_type
{ static constexpr auto _S_kind = _Integer_kind::_None; };
template<>
struct __is_integral_helper<bool>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_None; };
template<>
struct __is_integral_helper<char>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_None; };
template<>
struct __is_integral_helper<signed char>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Signed; };
template<>
struct __is_integral_helper<unsigned char>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Unsigned; };
// We want is_integral<wchar_t> to be true (and make_signed/unsigned to work)
// even when libc doesn't provide working <wchar.h> and related functions,
// so don't check _GLIBCXX_USE_WCHAR_T here.
template<>
struct __is_integral_helper<wchar_t>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_None; };
#ifdef _GLIBCXX_USE_CHAR8_T
template<>
struct __is_integral_helper<char8_t>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_None; };
#endif
template<>
struct __is_integral_helper<char16_t>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_None; };
template<>
struct __is_integral_helper<char32_t>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_None; };
template<>
struct __is_integral_helper<short>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Signed; };
template<>
struct __is_integral_helper<unsigned short>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Unsigned; };
template<>
struct __is_integral_helper<int>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Signed; };
template<>
struct __is_integral_helper<unsigned int>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Unsigned; };
template<>
struct __is_integral_helper<long>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Signed; };
template<>
struct __is_integral_helper<unsigned long>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Unsigned; };
template<>
struct __is_integral_helper<long long>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Signed; };
template<>
struct __is_integral_helper<unsigned long long>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Unsigned; };
// Conditionalizing on __STRICT_ANSI__ here will break any port that
// uses one of these types for size_t.
#if defined(__GLIBCXX_TYPE_INT_N_0)
__extension__
template<>
struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_0>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Signed; };
__extension__
template<>
struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_0>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Unsigned; };
#endif
#if defined(__GLIBCXX_TYPE_INT_N_1)
__extension__
template<>
struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_1>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Signed; };
__extension__
template<>
struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_1>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Unsigned; };
#endif
#if defined(__GLIBCXX_TYPE_INT_N_2)
__extension__
template<>
struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_2>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Signed; };
__extension__
template<>
struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_2>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Unsigned; };
#endif
#if defined(__GLIBCXX_TYPE_INT_N_3)
__extension__
template<>
struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_3>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Signed; };
__extension__
template<>
struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_3>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Unsigned; };
#endif
#if defined __SIZEOF_INT128__ && defined __STRICT_ANSI__
__extension__
template<>
struct __is_integral_helper<__int128>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Signed; };
__extension__
template<>
struct __is_integral_helper<unsigned __int128>
: public true_type
{ static constexpr auto _S_kind = _Integer_kind::_Unsigned; };
#endif
// Check if a type is one of the signed integer types.
template<typename _Tp>
using __is_signed_integer
= __bool_constant<__is_integral_helper<_Tp>::_S_kind
== _Integer_kind::_Signed>;
// Check if a type is one of the unsigned integer types.
template<typename _Tp>
using __is_unsigned_integer
= __bool_constant<__is_integral_helper<_Tp>::_S_kind
== _Integer_kind::_Unsigned>;
// Check if a type is one of the signed or unsigned integer types.
// i.e. an integral type except bool, char, wchar_t, and charN_t.
template<typename _Tp>
using __is_signed_or_unsigned_integer
= __bool_constant<__is_integral_helper<_Tp>::_S_kind
!= _Integer_kind::_None>;
/// @endcond
/// is_integral
template<typename _Tp>
struct is_integral
: public __is_integral_helper<__remove_cv_t<_Tp>>::type
{ };
/// @cond undocumented
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 { };
#ifdef __STDCPP_FLOAT16_T__
template<>
struct __is_floating_point_helper<_Float16>
: public true_type { };
#endif
#ifdef __STDCPP_FLOAT32_T__
template<>
struct __is_floating_point_helper<_Float32>
: public true_type { };
#endif
#ifdef __STDCPP_FLOAT64_T__
template<>
struct __is_floating_point_helper<_Float64>
: public true_type { };
#endif
#ifdef __STDCPP_FLOAT128_T__
template<>
struct __is_floating_point_helper<_Float128>
: public true_type { };
#endif
#ifdef __STDCPP_BFLOAT16_T__
template<>
struct __is_floating_point_helper<__gnu_cxx::__bfloat16_t>
: public true_type { };
#endif
#if defined(_GLIBCXX_USE_FLOAT128) && !defined(__CUDACC__)
template<>
struct __is_floating_point_helper<__float128>
: public true_type { };
#endif
/// @endcond
/// is_floating_point
template<typename _Tp>
struct is_floating_point
: public __is_floating_point_helper<__remove_cv_t<_Tp>>::type
{ };
/// is_array
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_array)
template<typename _Tp>
struct is_array
: public __bool_constant<__is_array(_Tp)>
{ };
#else
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 { };
#endif
/// is_pointer
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer)
template<typename _Tp>
struct is_pointer
: public __bool_constant<__is_pointer(_Tp)>
{ };
#else
template<typename _Tp>
struct is_pointer
: public false_type { };
template<typename _Tp>
struct is_pointer<_Tp*>
: public true_type { };
template<typename _Tp>
struct is_pointer<_Tp* const>
: public true_type { };
template<typename _Tp>
struct is_pointer<_Tp* volatile>
: public true_type { };
template<typename _Tp>
struct is_pointer<_Tp* const volatile>
: public true_type { };
#endif
/// 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 { };
/// is_member_object_pointer
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_member_object_pointer)
template<typename _Tp>
struct is_member_object_pointer
: public __bool_constant<__is_member_object_pointer(_Tp)>
{ };
#else
template<typename _Tp>
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 __not_<is_function<_Tp>>::type { };
template<typename _Tp>
struct is_member_object_pointer
: public __is_member_object_pointer_helper<__remove_cv_t<_Tp>>::type
{ };
#endif
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_member_function_pointer)
/// is_member_function_pointer
template<typename _Tp>
struct is_member_function_pointer
: public __bool_constant<__is_member_function_pointer(_Tp)>
{ };
#else
template<typename _Tp>
struct is_function;
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 is_function<_Tp>::type { };
/// is_member_function_pointer
template<typename _Tp>
struct is_member_function_pointer
: public __is_member_function_pointer_helper<__remove_cv_t<_Tp>>::type
{ };
#endif
/// is_enum
template<typename _Tp>
struct is_enum
: public __bool_constant<__is_enum(_Tp)>
{ };
/// is_union
template<typename _Tp>
struct is_union
: public __bool_constant<__is_union(_Tp)>
{ };
/// is_class
template<typename _Tp>
struct is_class
: public __bool_constant<__is_class(_Tp)>
{ };
/// is_function
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_function)
template<typename _Tp>
struct is_function
: public __bool_constant<__is_function(_Tp)>
{ };
#else
template<typename _Tp>
struct is_function
: public __bool_constant<!is_const<const _Tp>::value> { };
template<typename _Tp>
struct is_function<_Tp&>
: public false_type { };
template<typename _Tp>
struct is_function<_Tp&&>
: public false_type { };
#endif
#if __cpp_impl_reflection >= 202506L // C++ >= 26
/// is_reflection
template<typename _Tp>
struct is_reflection
: public false_type { };
template<>
struct is_reflection<decltype(^^int)>
: public true_type { };
template<>
struct is_reflection<const decltype(^^int)>
: public true_type { };
template<>
struct is_reflection<volatile decltype(^^int)>
: public true_type { };
template<>
struct is_reflection<const volatile decltype(^^int)>
: public true_type { };
#endif
#ifdef __cpp_lib_is_null_pointer // C++ >= 11
/// is_null_pointer (LWG 2247).
template<typename _Tp>
struct is_null_pointer
: public false_type { };
template<>
struct is_null_pointer<std::nullptr_t>
: public true_type { };
template<>
struct is_null_pointer<const std::nullptr_t>
: public true_type { };
template<>
struct is_null_pointer<volatile std::nullptr_t>
: public true_type { };
template<>
struct is_null_pointer<const volatile std::nullptr_t>
: public true_type { };
/// __is_nullptr_t (deprecated extension).
/// @deprecated Non-standard. Use `is_null_pointer` instead.
template<typename _Tp>
struct __is_nullptr_t
: public is_null_pointer<_Tp>
{ } _GLIBCXX_DEPRECATED_SUGGEST("std::is_null_pointer");
#endif // __cpp_lib_is_null_pointer
// Composite type categories.
/// is_reference
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_reference)
template<typename _Tp>
struct is_reference
: public __bool_constant<__is_reference(_Tp)>
{ };
#else
template<typename _Tp>
struct is_reference
: public false_type
{ };
template<typename _Tp>
struct is_reference<_Tp&>
: public true_type
{ };
template<typename _Tp>
struct is_reference<_Tp&&>
: public true_type
{ };
#endif
/// 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_null_pointer<_Tp>
#if __cpp_impl_reflection >= 202506L
, is_reflection<_Tp>
#endif
>::type
{ };
/// is_object
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_object)
template<typename _Tp>
struct is_object
: public __bool_constant<__is_object(_Tp)>
{ };
#else
template<typename _Tp>
struct is_object
: public __not_<__or_<is_function<_Tp>, is_reference<_Tp>,
is_void<_Tp>>>::type
{ };
#endif
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_null_pointer<_Tp>
#if __cpp_impl_reflection >= 202506L
, is_reflection<_Tp>
#endif
>::type
{ };
/// is_compound
template<typename _Tp>
struct is_compound
: public __bool_constant<!is_fundamental<_Tp>::value> { };
/// is_member_pointer
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_member_pointer)
template<typename _Tp>
struct is_member_pointer
: public __bool_constant<__is_member_pointer(_Tp)>
{ };
#else
/// @cond undocumented
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 { };
/// @endcond
template<typename _Tp>
struct is_member_pointer
: public __is_member_pointer_helper<__remove_cv_t<_Tp>>::type
{ };
#endif
template<typename, typename>
struct is_same;
/// @cond undocumented
template<typename _Tp, typename... _Types>
using __is_one_of = __or_<is_same<_Tp, _Types>...>;
// __void_t (std::void_t for C++11)
template<typename...> using __void_t = void;
/// @endcond
// Type properties.
/// is_const
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_const)
template<typename _Tp>
struct is_const
: public __bool_constant<__is_const(_Tp)>
{ };
#else
template<typename>
struct is_const
: public false_type { };
template<typename _Tp>
struct is_const<_Tp const>
: public true_type { };
#endif
/// is_volatile
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_volatile)
template<typename _Tp>
struct is_volatile
: public __bool_constant<__is_volatile(_Tp)>
{ };
#else
template<typename>
struct is_volatile
: public false_type { };
template<typename _Tp>
struct is_volatile<_Tp volatile>
: public true_type { };
#endif
/** is_trivial
* @deprecated Deprecated in C++26.
* Use a combination of one or more more specialized type traits instead,
* such as `is_trivially_default_constructible`,
* `is_trivially_copy_constructible`, `is_trivially_copy_assignable`,
* etc., depending on the exact check(s) needed.
*/
template<typename _Tp>
struct
_GLIBCXX26_DEPRECATED_SUGGEST("is_trivially_default_constructible && is_trivially_copyable")
is_trivial
: public __bool_constant<__is_trivial(_Tp)>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_trivially_copyable
template<typename _Tp>
struct is_trivially_copyable
: public __bool_constant<__is_trivially_copyable(_Tp)>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_standard_layout
template<typename _Tp>
struct is_standard_layout
: public __bool_constant<__is_standard_layout(_Tp)>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/** is_pod
* @deprecated Deprecated in C++20.
* Use `is_standard_layout && is_trivial` instead.
*/
// Could use is_standard_layout && is_trivial instead of the builtin.
template<typename _Tp>
struct
_GLIBCXX20_DEPRECATED_SUGGEST("is_standard_layout && is_trivial")
is_pod
: public __bool_constant<__is_pod(_Tp)>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/** is_literal_type
* @deprecated Deprecated in C++17, removed in C++20.
* The idea of a literal type isn't useful.
*/
template<typename _Tp>
struct
_GLIBCXX17_DEPRECATED
is_literal_type
: public __bool_constant<__is_literal_type(_Tp)>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_empty
template<typename _Tp>
struct is_empty
: public __bool_constant<__is_empty(_Tp)>
{ };
/// is_polymorphic
template<typename _Tp>
struct is_polymorphic
: public __bool_constant<__is_polymorphic(_Tp)>
{ };
#ifdef __cpp_lib_is_final // C++ >= 14
/// is_final
/// @since C++14
template<typename _Tp>
struct is_final
: public __bool_constant<__is_final(_Tp)>
{ };
#endif
/// is_abstract
template<typename _Tp>
struct is_abstract
: public __bool_constant<__is_abstract(_Tp)>
{ };
/// @cond undocumented
template<typename _Tp,
bool = is_arithmetic<_Tp>::value>
struct __is_signed_helper
: public false_type { };
template<typename _Tp>
struct __is_signed_helper<_Tp, true>
: public __bool_constant<_Tp(-1) < _Tp(0)>
{ };
/// @endcond
/// is_signed
template<typename _Tp>
struct is_signed
: public __is_signed_helper<_Tp>::type
{ };
/// is_unsigned
template<typename _Tp>
struct is_unsigned
: public __and_<is_arithmetic<_Tp>, __not_<is_signed<_Tp>>>::type
{ };
/// @cond undocumented
template<typename _Tp, typename _Up = _Tp&&>
_Up
__declval(int);
template<typename _Tp>
_Tp
__declval(long);
/// @endcond
template<typename _Tp>
auto declval() noexcept -> decltype(__declval<_Tp>(0));
template<typename>
struct remove_all_extents;
/// @cond undocumented
template<typename _Tp>
struct __is_array_known_bounds
: public false_type
{ };
template<typename _Tp, size_t _Size>
struct __is_array_known_bounds<_Tp[_Size]>
: public true_type
{ };
template<typename _Tp>
struct __is_array_unknown_bounds
: public false_type
{ };
template<typename _Tp>
struct __is_array_unknown_bounds<_Tp[]>
: public true_type
{ };
/// @endcond
// Destructible and constructible type properties.
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_destructible)
/// is_destructible
template<typename _Tp>
struct is_destructible
: public __bool_constant<__is_destructible(_Tp)>
{ };
#else
/// @cond undocumented
// 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
{
using type = decltype(__test<_Tp>(0));
};
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 { };
/// @endcond
/// is_destructible
template<typename _Tp>
struct is_destructible
: public __is_destructible_safe<_Tp>::type
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
#endif
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_nothrow_destructible)
/// is_nothrow_destructible
template<typename _Tp>
struct is_nothrow_destructible
: public __bool_constant<__is_nothrow_destructible(_Tp)>
{ };
#else
/// @cond undocumented
// 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 __bool_constant<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
{
using type = decltype(__test<_Tp>(0));
};
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 { };
/// @endcond
/// is_nothrow_destructible
template<typename _Tp>
struct is_nothrow_destructible
: public __is_nt_destructible_safe<_Tp>::type
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
#endif
/// @cond undocumented
template<typename _Tp, typename... _Args>
using __is_constructible_impl
= __bool_constant<__is_constructible(_Tp, _Args...)>;
/// @endcond
/// is_constructible
template<typename _Tp, typename... _Args>
struct is_constructible
: public __is_constructible_impl<_Tp, _Args...>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_default_constructible
template<typename _Tp>
struct is_default_constructible
: public __is_constructible_impl<_Tp>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// @cond undocumented
#if _GLIBCXX_USE_BUILTIN_TRAIT(__add_lvalue_reference)
template<typename _Tp>
using __add_lval_ref_t = __add_lvalue_reference(_Tp);
#else
template<typename _Tp, typename = void>
struct __add_lvalue_reference_helper
{ using type = _Tp; };
template<typename _Tp>
struct __add_lvalue_reference_helper<_Tp, __void_t<_Tp&>>
{ using type = _Tp&; };
template<typename _Tp>
using __add_lval_ref_t = typename __add_lvalue_reference_helper<_Tp>::type;
#endif
/// @endcond
/// is_copy_constructible
template<typename _Tp>
struct is_copy_constructible
: public __is_constructible_impl<_Tp, __add_lval_ref_t<const _Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// @cond undocumented
#if _GLIBCXX_USE_BUILTIN_TRAIT(__add_rvalue_reference)
template<typename _Tp>
using __add_rval_ref_t = __add_rvalue_reference(_Tp);
#else
template<typename _Tp, typename = void>
struct __add_rvalue_reference_helper
{ using type = _Tp; };
template<typename _Tp>
struct __add_rvalue_reference_helper<_Tp, __void_t<_Tp&&>>
{ using type = _Tp&&; };
template<typename _Tp>
using __add_rval_ref_t = typename __add_rvalue_reference_helper<_Tp>::type;
#endif
/// @endcond
/// is_move_constructible
template<typename _Tp>
struct is_move_constructible
: public __is_constructible_impl<_Tp, __add_rval_ref_t<_Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// @cond undocumented
template<typename _Tp, typename... _Args>
using __is_nothrow_constructible_impl
= __bool_constant<__is_nothrow_constructible(_Tp, _Args...)>;
/// @endcond
/// is_nothrow_constructible
template<typename _Tp, typename... _Args>
struct is_nothrow_constructible
: public __is_nothrow_constructible_impl<_Tp, _Args...>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_nothrow_default_constructible
template<typename _Tp>
struct is_nothrow_default_constructible
: public __is_nothrow_constructible_impl<_Tp>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_nothrow_copy_constructible
template<typename _Tp>
struct is_nothrow_copy_constructible
: public __is_nothrow_constructible_impl<_Tp, __add_lval_ref_t<const _Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_nothrow_move_constructible
template<typename _Tp>
struct is_nothrow_move_constructible
: public __is_nothrow_constructible_impl<_Tp, __add_rval_ref_t<_Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// @cond undocumented
template<typename _Tp, typename _Up>
using __is_assignable_impl = __bool_constant<__is_assignable(_Tp, _Up)>;
/// @endcond
/// is_assignable
template<typename _Tp, typename _Up>
struct is_assignable
: public __is_assignable_impl<_Tp, _Up>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_copy_assignable
template<typename _Tp>
struct is_copy_assignable
: public __is_assignable_impl<__add_lval_ref_t<_Tp>,
__add_lval_ref_t<const _Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_move_assignable
template<typename _Tp>
struct is_move_assignable
: public __is_assignable_impl<__add_lval_ref_t<_Tp>, __add_rval_ref_t<_Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// @cond undocumented
template<typename _Tp, typename _Up>
using __is_nothrow_assignable_impl
= __bool_constant<__is_nothrow_assignable(_Tp, _Up)>;
/// @endcond
/// is_nothrow_assignable
template<typename _Tp, typename _Up>
struct is_nothrow_assignable
: public __is_nothrow_assignable_impl<_Tp, _Up>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_nothrow_copy_assignable
template<typename _Tp>
struct is_nothrow_copy_assignable
: public __is_nothrow_assignable_impl<__add_lval_ref_t<_Tp>,
__add_lval_ref_t<const _Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_nothrow_move_assignable
template<typename _Tp>
struct is_nothrow_move_assignable
: public __is_nothrow_assignable_impl<__add_lval_ref_t<_Tp>,
__add_rval_ref_t<_Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// @cond undocumented
template<typename _Tp, typename... _Args>
using __is_trivially_constructible_impl
= __bool_constant<__is_trivially_constructible(_Tp, _Args...)>;
/// @endcond
/// is_trivially_constructible
template<typename _Tp, typename... _Args>
struct is_trivially_constructible
: public __is_trivially_constructible_impl<_Tp, _Args...>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_trivially_default_constructible
template<typename _Tp>
struct is_trivially_default_constructible
: public __is_trivially_constructible_impl<_Tp>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
#if __cpp_variable_templates && __cpp_concepts
template<typename _Tp>
constexpr bool __is_implicitly_default_constructible_v
= requires (void(&__f)(_Tp)) { __f({}); };
template<typename _Tp>
struct __is_implicitly_default_constructible
: __bool_constant<__is_implicitly_default_constructible_v<_Tp>>
{ };
#else
struct __do_is_implicitly_default_constructible_impl
{
template <typename _Tp>
static void __helper(const _Tp&);
template <typename _Tp>
static true_type __test(const _Tp&,
decltype(__helper<const _Tp&>({}))* = 0);
static false_type __test(...);
};
template<typename _Tp>
struct __is_implicitly_default_constructible_impl
: public __do_is_implicitly_default_constructible_impl
{
using type = decltype(__test(declval<_Tp>()));
};
template<typename _Tp>
struct __is_implicitly_default_constructible_safe
: public __is_implicitly_default_constructible_impl<_Tp>::type
{ };
template <typename _Tp>
struct __is_implicitly_default_constructible
: public __and_<__is_constructible_impl<_Tp>,
__is_implicitly_default_constructible_safe<_Tp>>::type
{ };
#endif
/// is_trivially_copy_constructible
template<typename _Tp>
struct is_trivially_copy_constructible
: public __is_trivially_constructible_impl<_Tp, __add_lval_ref_t<const _Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_trivially_move_constructible
template<typename _Tp>
struct is_trivially_move_constructible
: public __is_trivially_constructible_impl<_Tp, __add_rval_ref_t<_Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// @cond undocumented
template<typename _Tp, typename _Up>
using __is_trivially_assignable_impl
= __bool_constant<__is_trivially_assignable(_Tp, _Up)>;
/// @endcond
/// is_trivially_assignable
template<typename _Tp, typename _Up>
struct is_trivially_assignable
: public __is_trivially_assignable_impl<_Tp, _Up>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_trivially_copy_assignable
template<typename _Tp>
struct is_trivially_copy_assignable
: public __is_trivially_assignable_impl<__add_lval_ref_t<_Tp>,
__add_lval_ref_t<const _Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_trivially_move_assignable
template<typename _Tp>
struct is_trivially_move_assignable
: public __is_trivially_assignable_impl<__add_lval_ref_t<_Tp>,
__add_rval_ref_t<_Tp>>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_trivially_destructible)
/// is_trivially_destructible
template<typename _Tp>
struct is_trivially_destructible
: public __bool_constant<__is_trivially_destructible(_Tp)>
{ };
#else
/// is_trivially_destructible
template<typename _Tp>
struct is_trivially_destructible
: public __and_<__is_destructible_safe<_Tp>,
__bool_constant<__has_trivial_destructor(_Tp)>>::type
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
#endif
/// has_virtual_destructor
template<typename _Tp>
struct has_virtual_destructor
: public __bool_constant<__has_virtual_destructor(_Tp)>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
// type property queries.
/// alignment_of
template<typename _Tp>
struct alignment_of
: public integral_constant<std::size_t, alignof(_Tp)>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// rank
#if _GLIBCXX_USE_BUILTIN_TRAIT(__array_rank) \
&& (!defined(__clang__) || __clang_major__ >= 20) // PR118559
template<typename _Tp>
struct rank
: public integral_constant<std::size_t, __array_rank(_Tp)> { };
#else
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> { };
#endif
/// extent
template<typename, unsigned _Uint = 0>
struct extent
: public integral_constant<size_t, 0> { };
template<typename _Tp, size_t _Size>
struct extent<_Tp[_Size], 0>
: public integral_constant<size_t, _Size> { };
template<typename _Tp, unsigned _Uint, size_t _Size>
struct extent<_Tp[_Size], _Uint>
: public extent<_Tp, _Uint - 1>::type { };
template<typename _Tp>
struct extent<_Tp[], 0>
: public integral_constant<size_t, 0> { };
template<typename _Tp, unsigned _Uint>
struct extent<_Tp[], _Uint>
: public extent<_Tp, _Uint - 1>::type { };
// Type relations.
/// is_same
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_same)
template<typename _Tp, typename _Up>
struct is_same
: public __bool_constant<__is_same(_Tp, _Up)>
{ };
#else
template<typename _Tp, typename _Up>
struct is_same
: public false_type
{ };
template<typename _Tp>
struct is_same<_Tp, _Tp>
: public true_type
{ };
#endif
/// is_base_of
template<typename _Base, typename _Derived>
struct is_base_of
: public __bool_constant<__is_base_of(_Base, _Derived)>
{ };
#ifdef __cpp_lib_is_virtual_base_of // C++ >= 26
/// is_virtual_base_of
/// @since C++26
template<typename _Base, typename _Derived>
struct is_virtual_base_of
: public bool_constant<__builtin_is_virtual_base_of(_Base, _Derived)>
{ };
#endif
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_convertible)
template<typename _From, typename _To>
struct is_convertible
: public __bool_constant<__is_convertible(_From, _To)>
{ };
#else
template<typename _From, typename _To,
bool = __or_<is_void<_From>, is_function<_To>,
is_array<_To>>::value>
struct __is_convertible_helper
{
using type = typename is_void<_To>::type;
};
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
template<typename _From, typename _To>
class __is_convertible_helper<_From, _To, false>
{
template<typename _To1>
static void __test_aux(_To1) noexcept;
template<typename _From1, typename _To1,
typename = decltype(__test_aux<_To1>(std::declval<_From1>()))>
static true_type
__test(int);
template<typename, typename>
static false_type
__test(...);
public:
using type = decltype(__test<_From, _To>(0));
};
#pragma GCC diagnostic pop
/// is_convertible
template<typename _From, typename _To>
struct is_convertible
: public __is_convertible_helper<_From, _To>::type
{ };
#endif
// helper trait for unique_ptr<T[]>, shared_ptr<T[]>, and span<T, N>
template<typename _ToElementType, typename _FromElementType>
using __is_array_convertible
= is_convertible<_FromElementType(*)[], _ToElementType(*)[]>;
#ifdef __cpp_lib_is_nothrow_convertible // C++ >= 20
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_nothrow_convertible)
/// is_nothrow_convertible_v
template<typename _From, typename _To>
inline constexpr bool is_nothrow_convertible_v
= __is_nothrow_convertible(_From, _To);
/// is_nothrow_convertible
template<typename _From, typename _To>
struct is_nothrow_convertible
: public bool_constant<is_nothrow_convertible_v<_From, _To>>
{ };
#else
template<typename _From, typename _To,
bool = __or_<is_void<_From>, is_function<_To>,
is_array<_To>>::value>
struct __is_nt_convertible_helper
: is_void<_To>
{ };
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
template<typename _From, typename _To>
class __is_nt_convertible_helper<_From, _To, false>
{
template<typename _To1>
static void __test_aux(_To1) noexcept;
template<typename _From1, typename _To1>
static
__bool_constant<noexcept(__test_aux<_To1>(std::declval<_From1>()))>
__test(int);
template<typename, typename>
static false_type
__test(...);
public:
using type = decltype(__test<_From, _To>(0));
};
#pragma GCC diagnostic pop
/// is_nothrow_convertible
template<typename _From, typename _To>
struct is_nothrow_convertible
: public __is_nt_convertible_helper<_From, _To>::type
{ };
/// is_nothrow_convertible_v
template<typename _From, typename _To>
inline constexpr bool is_nothrow_convertible_v
= is_nothrow_convertible<_From, _To>::value;
#endif
#endif // __cpp_lib_is_nothrow_convertible
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wc++14-extensions" // for variable templates
template<typename _Tp, typename... _Args>
struct __is_nothrow_new_constructible_impl
: __bool_constant<
noexcept(::new(std::declval<void*>()) _Tp(std::declval<_Args>()...))
>
{ };
template<typename _Tp, typename... _Args>
_GLIBCXX17_INLINE constexpr bool __is_nothrow_new_constructible
= __and_<is_constructible<_Tp, _Args...>,
__is_nothrow_new_constructible_impl<_Tp, _Args...>>::value;
#pragma GCC diagnostic pop
// Const-volatile modifications.
/// remove_const
template<typename _Tp>
struct remove_const
{ using type = _Tp; };
template<typename _Tp>
struct remove_const<_Tp const>
{ using type = _Tp; };
/// remove_volatile
template<typename _Tp>
struct remove_volatile
{ using type = _Tp; };
template<typename _Tp>
struct remove_volatile<_Tp volatile>
{ using type = _Tp; };
/// remove_cv
#if _GLIBCXX_USE_BUILTIN_TRAIT(__remove_cv)
template<typename _Tp>
struct remove_cv
{ using type = __remove_cv(_Tp); };
#else
template<typename _Tp>
struct remove_cv
{ using type = _Tp; };
template<typename _Tp>
struct remove_cv<const _Tp>
{ using type = _Tp; };
template<typename _Tp>
struct remove_cv<volatile _Tp>
{ using type = _Tp; };
template<typename _Tp>
struct remove_cv<const volatile _Tp>
{ using type = _Tp; };
#endif
/// add_const
template<typename _Tp>
struct add_const
{ using type = _Tp const; };
/// add_volatile
template<typename _Tp>
struct add_volatile
{ using type = _Tp volatile; };
/// add_cv
template<typename _Tp>
struct add_cv
{ using type = _Tp const volatile; };
#ifdef __cpp_lib_transformation_trait_aliases // C++ >= 14
/// Alias template for remove_const
template<typename _Tp>
using remove_const_t = typename remove_const<_Tp>::type;
/// Alias template for remove_volatile
template<typename _Tp>
using remove_volatile_t = typename remove_volatile<_Tp>::type;
/// Alias template for remove_cv
template<typename _Tp>
using remove_cv_t = typename remove_cv<_Tp>::type;
/// Alias template for add_const
template<typename _Tp>
using add_const_t = typename add_const<_Tp>::type;
/// Alias template for add_volatile
template<typename _Tp>
using add_volatile_t = typename add_volatile<_Tp>::type;
/// Alias template for add_cv
template<typename _Tp>
using add_cv_t = typename add_cv<_Tp>::type;
#endif
// Reference transformations.
/// remove_reference
#if _GLIBCXX_USE_BUILTIN_TRAIT(__remove_reference)
template<typename _Tp>
struct remove_reference
{ using type = __remove_reference(_Tp); };
#else
template<typename _Tp>
struct remove_reference
{ using type = _Tp; };
template<typename _Tp>
struct remove_reference<_Tp&>
{ using type = _Tp; };
template<typename _Tp>
struct remove_reference<_Tp&&>
{ using type = _Tp; };
#endif
/// add_lvalue_reference
template<typename _Tp>
struct add_lvalue_reference
{ using type = __add_lval_ref_t<_Tp>; };
/// add_rvalue_reference
template<typename _Tp>
struct add_rvalue_reference
{ using type = __add_rval_ref_t<_Tp>; };
#if __cplusplus > 201103L
/// Alias template for remove_reference
template<typename _Tp>
using remove_reference_t = typename remove_reference<_Tp>::type;
/// Alias template for add_lvalue_reference
template<typename _Tp>
using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
/// Alias template for add_rvalue_reference
template<typename _Tp>
using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
#endif
// Sign modifications.
/// @cond undocumented
// 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>
{ using __type = _Unqualified; };
template<typename _Unqualified>
struct __cv_selector<_Unqualified, false, true>
{ using __type = volatile _Unqualified; };
template<typename _Unqualified>
struct __cv_selector<_Unqualified, true, false>
{ using __type = const _Unqualified; };
template<typename _Unqualified>
struct __cv_selector<_Unqualified, true, true>
{ using __type = const volatile _Unqualified; };
template<typename _Qualified, typename _Unqualified,
bool _IsConst = is_const<_Qualified>::value,
bool _IsVol = is_volatile<_Qualified>::value>
class __match_cv_qualifiers
{
using __match = __cv_selector<_Unqualified, _IsConst, _IsVol>;
public:
using __type = typename __match::__type;
};
// Utility for finding the unsigned versions of signed integral types.
template<typename _Tp>
struct __make_unsigned
{ using __type = _Tp; };
template<>
struct __make_unsigned<char>
{ using __type = unsigned char; };
template<>
struct __make_unsigned<signed char>
{ using __type = unsigned char; };
template<>
struct __make_unsigned<short>
{ using __type = unsigned short; };
template<>
struct __make_unsigned<int>
{ using __type = unsigned int; };
template<>
struct __make_unsigned<long>
{ using __type = unsigned long; };
template<>
struct __make_unsigned<long long>
{ using __type = unsigned long long; };
#if defined(__GLIBCXX_TYPE_INT_N_0)
__extension__
template<>
struct __make_unsigned<__GLIBCXX_TYPE_INT_N_0>
{ using __type = unsigned __GLIBCXX_TYPE_INT_N_0; };
#endif
#if defined(__GLIBCXX_TYPE_INT_N_1)
__extension__
template<>
struct __make_unsigned<__GLIBCXX_TYPE_INT_N_1>
{ using __type = unsigned __GLIBCXX_TYPE_INT_N_1; };
#endif
#if defined(__GLIBCXX_TYPE_INT_N_2)
__extension__
template<>
struct __make_unsigned<__GLIBCXX_TYPE_INT_N_2>
{ using __type = unsigned __GLIBCXX_TYPE_INT_N_2; };
#endif
#if defined(__GLIBCXX_TYPE_INT_N_3)
__extension__
template<>
struct __make_unsigned<__GLIBCXX_TYPE_INT_N_3>
{ using __type = unsigned __GLIBCXX_TYPE_INT_N_3; };
#endif
#if defined __SIZEOF_INT128__ && defined __STRICT_ANSI__
__extension__
template<>
struct __make_unsigned<__int128>
{ using __type = unsigned __int128; };
#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)>
class __make_unsigned_selector;
template<typename _Tp>
class __make_unsigned_selector<_Tp, true, false>
{
using __unsigned_type
= typename __make_unsigned<__remove_cv_t<_Tp>>::__type;
public:
using __type
= typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
};
class __make_unsigned_selector_base
{
protected:
template<typename...> struct _List { };
template<typename _Tp, typename... _Up>
struct _List<_Tp, _Up...> : _List<_Up...>
{ static constexpr size_t __size = sizeof(_Tp); };
template<size_t _Sz, typename _Tp, bool = (_Sz <= _Tp::__size)>
struct __select;
template<size_t _Sz, typename _Uint, typename... _UInts>
struct __select<_Sz, _List<_Uint, _UInts...>, true>
{ using __type = _Uint; };
template<size_t _Sz, typename _Uint, typename... _UInts>
struct __select<_Sz, _List<_Uint, _UInts...>, false>
: __select<_Sz, _List<_UInts...>>
{ };
};
// Choose unsigned integer type with the smallest rank and same size as _Tp
template<typename _Tp>
class __make_unsigned_selector<_Tp, false, true>
: __make_unsigned_selector_base
{
// With -fshort-enums, an enum may be as small as a char.
__extension__
using _UInts = _List<unsigned char, unsigned short, unsigned int,
unsigned long, unsigned long long
#ifdef __SIZEOF_INT128__
, unsigned __int128
#endif
>;
using __unsigned_type = typename __select<sizeof(_Tp), _UInts>::__type;
public:
using __type
= typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
};
// wchar_t, char8_t, char16_t and char32_t are integral types but are
// neither signed integer types nor unsigned integer types, so must be
// transformed to the unsigned integer type with the smallest rank.
// Use the partial specialization for enumeration types to do that.
template<>
struct __make_unsigned<wchar_t>
{
using __type
= typename __make_unsigned_selector<wchar_t, false, true>::__type;
};
#ifdef _GLIBCXX_USE_CHAR8_T
template<>
struct __make_unsigned<char8_t>
{
using __type
= typename __make_unsigned_selector<char8_t, false, true>::__type;
};
#endif
template<>
struct __make_unsigned<char16_t>
{
using __type
= typename __make_unsigned_selector<char16_t, false, true>::__type;
};
template<>
struct __make_unsigned<char32_t>
{
using __type
= typename __make_unsigned_selector<char32_t, false, true>::__type;
};
/// @endcond
// Given an integral/enum type, return the corresponding unsigned
// integer type.
// Primary template.
/// make_unsigned
template<typename _Tp>
struct make_unsigned
{ using type = typename __make_unsigned_selector<_Tp>::__type; };
// Integral, but don't define.
template<> struct make_unsigned<bool>;
template<> struct make_unsigned<bool const>;
template<> struct make_unsigned<bool volatile>;
template<> struct make_unsigned<bool const volatile>;
/// @cond undocumented
// Utility for finding the signed versions of unsigned integral types.
template<typename _Tp>
struct __make_signed
{ using __type = _Tp; };
template<>
struct __make_signed<char>
{ using __type = signed char; };
template<>
struct __make_signed<unsigned char>
{ using __type = signed char; };
template<>
struct __make_signed<unsigned short>
{ using __type = signed short; };
template<>
struct __make_signed<unsigned int>
{ using __type = signed int; };
template<>
struct __make_signed<unsigned long>
{ using __type = signed long; };
template<>
struct __make_signed<unsigned long long>
{ using __type = signed long long; };
#if defined(__GLIBCXX_TYPE_INT_N_0)
__extension__
template<>
struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_0>
{ using __type = __GLIBCXX_TYPE_INT_N_0; };
#endif
#if defined(__GLIBCXX_TYPE_INT_N_1)
__extension__
template<>
struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_1>
{ using __type = __GLIBCXX_TYPE_INT_N_1; };
#endif
#if defined(__GLIBCXX_TYPE_INT_N_2)
__extension__
template<>
struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_2>
{ using __type = __GLIBCXX_TYPE_INT_N_2; };
#endif
#if defined(__GLIBCXX_TYPE_INT_N_3)
__extension__
template<>
struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_3>
{ using __type = __GLIBCXX_TYPE_INT_N_3; };
#endif
#if defined __SIZEOF_INT128__ && defined __STRICT_ANSI__
__extension__
template<>
struct __make_signed<unsigned __int128>
{ using __type = __int128; };
#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)>
class __make_signed_selector;
template<typename _Tp>
class __make_signed_selector<_Tp, true, false>
{
using __signed_type
= typename __make_signed<__remove_cv_t<_Tp>>::__type;
public:
using __type
= typename __match_cv_qualifiers<_Tp, __signed_type>::__type;
};
// Choose signed integer type with the smallest rank and same size as _Tp
template<typename _Tp>
class __make_signed_selector<_Tp, false, true>
{
using __unsigned_type = typename __make_unsigned_selector<_Tp>::__type;
public:
using __type = typename __make_signed_selector<__unsigned_type>::__type;
};
// wchar_t, char16_t and char32_t are integral types but are neither
// signed integer types nor unsigned integer types, so must be
// transformed to the signed integer type with the smallest rank.
// Use the partial specialization for enumeration types to do that.
template<>
struct __make_signed<wchar_t>
{
using __type
= typename __make_signed_selector<wchar_t, false, true>::__type;
};
#if defined(_GLIBCXX_USE_CHAR8_T)
template<>
struct __make_signed<char8_t>
{
using __type
= typename __make_signed_selector<char8_t, false, true>::__type;
};
#endif
template<>
struct __make_signed<char16_t>
{
using __type
= typename __make_signed_selector<char16_t, false, true>::__type;
};
template<>
struct __make_signed<char32_t>
{
using __type
= typename __make_signed_selector<char32_t, false, true>::__type;
};
/// @endcond
// Given an integral/enum type, return the corresponding signed
// integer type.
// Primary template.
/// make_signed
template<typename _Tp>
struct make_signed
{ using type = typename __make_signed_selector<_Tp>::__type; };
// Integral, but don't define.
template<> struct make_signed<bool>;
template<> struct make_signed<bool const>;
template<> struct make_signed<bool volatile>;
template<> struct make_signed<bool const volatile>;
#if __cplusplus > 201103L
/// Alias template for make_signed
template<typename _Tp>
using make_signed_t = typename make_signed<_Tp>::type;
/// Alias template for make_unsigned
template<typename _Tp>
using make_unsigned_t = typename make_unsigned<_Tp>::type;
#endif
// Array modifications.
/// remove_extent
#if _GLIBCXX_USE_BUILTIN_TRAIT(__remove_extent)
template<typename _Tp>
struct remove_extent
{ using type = __remove_extent(_Tp); };
#else
template<typename _Tp>
struct remove_extent
{ using type = _Tp; };
template<typename _Tp, std::size_t _Size>
struct remove_extent<_Tp[_Size]>
{ using type = _Tp; };
template<typename _Tp>
struct remove_extent<_Tp[]>
{ using type = _Tp; };
#endif
/// remove_all_extents
#if _GLIBCXX_USE_BUILTIN_TRAIT(__remove_all_extents)
template<typename _Tp>
struct remove_all_extents
{ using type = __remove_all_extents(_Tp); };
#else
template<typename _Tp>
struct remove_all_extents
{ using type = _Tp; };
template<typename _Tp, std::size_t _Size>
struct remove_all_extents<_Tp[_Size]>
{ using type = typename remove_all_extents<_Tp>::type; };
template<typename _Tp>
struct remove_all_extents<_Tp[]>
{ using type = typename remove_all_extents<_Tp>::type; };
#endif
#if __cplusplus > 201103L
/// Alias template for remove_extent
template<typename _Tp>
using remove_extent_t = typename remove_extent<_Tp>::type;
/// Alias template for remove_all_extents
template<typename _Tp>
using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
#endif
// Pointer modifications.
/// remove_pointer
#if _GLIBCXX_USE_BUILTIN_TRAIT(__remove_pointer)
template<typename _Tp>
struct remove_pointer
{ using type = __remove_pointer(_Tp); };
#else
template<typename _Tp, typename>
struct __remove_pointer_helper
{ using type = _Tp; };
template<typename _Tp, typename _Up>
struct __remove_pointer_helper<_Tp, _Up*>
{ using type = _Up; };
template<typename _Tp>
struct remove_pointer
: public __remove_pointer_helper<_Tp, __remove_cv_t<_Tp>>
{ };
#endif
/// add_pointer
#if _GLIBCXX_USE_BUILTIN_TRAIT(__add_pointer)
template<typename _Tp>
struct add_pointer
{ using type = __add_pointer(_Tp); };
#else
template<typename _Tp, typename = void>
struct __add_pointer_helper
{ using type = _Tp; };
template<typename _Tp>
struct __add_pointer_helper<_Tp, __void_t<_Tp*>>
{ using type = _Tp*; };
template<typename _Tp>
struct add_pointer
: public __add_pointer_helper<_Tp>
{ };
template<typename _Tp>
struct add_pointer<_Tp&>
{ using type = _Tp*; };
template<typename _Tp>
struct add_pointer<_Tp&&>
{ using type = _Tp*; };
#endif
#if __cplusplus > 201103L
/// Alias template for remove_pointer
template<typename _Tp>
using remove_pointer_t = typename remove_pointer<_Tp>::type;
/// Alias template for add_pointer
template<typename _Tp>
using add_pointer_t = typename add_pointer<_Tp>::type;
#endif
/// @cond undocumented
// Aligned to maximum fundamental alignment
struct __attribute__((__aligned__)) __aligned_storage_max_align_t
{ };
constexpr size_t
__aligned_storage_default_alignment([[__maybe_unused__]] size_t __len)
{
#if _GLIBCXX_INLINE_VERSION
using _Max_align
= integral_constant<size_t, alignof(__aligned_storage_max_align_t)>;
return __len > (_Max_align::value / 2)
? _Max_align::value
# if _GLIBCXX_USE_BUILTIN_TRAIT(__builtin_clzg)
: 1 << (__SIZE_WIDTH__ - __builtin_clzg(__len - 1u));
# else
: 1 << (__LLONG_WIDTH__ - __builtin_clzll(__len - 1ull));
# endif
#else
// Returning a fixed value is incorrect, but kept for ABI compatibility.
// XXX GLIBCXX_ABI Deprecated
return alignof(__aligned_storage_max_align_t);
#endif
}
/// @endcond
/**
* @brief Aligned storage
*
* The member typedef `type` is 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`.
*
* It is important to use the nested `type` as uninitialized storage,
* not the `std::aligned_storage` type itself which is an empty class
* with 1-byte alignment. So this is correct:
*
* `typename std::aligned_storage<sizeof(X), alignof(X)>::type m_xobj;`
*
* This is wrong:
*
* `std::aligned_storage<sizeof(X), alignof(X)> m_xobj;`
*
* In C++14 and later `std::aligned_storage_t<sizeof(X), alignof(X)>`
* can be used to refer to the `type` member typedef.
*
* The default value of _Align is supposed to be the most stringent
* fundamental alignment requirement for any C++ object type whose size
* is no greater than `_Len` (see [basic.align] in the C++ standard).
*
* @bug In this implementation the default value for _Align is always the
* maximum fundamental alignment, i.e. `alignof(max_align_t)`, which is
* incorrect. It should be an alignment value no greater than `_Len`.
*
* @deprecated Deprecated in C++23. Uses can be replaced by an
* array `std::byte[_Len]` declared with `alignas(_Align)`.
*/
template<size_t _Len,
size_t _Align = __aligned_storage_default_alignment(_Len)>
struct
_GLIBCXX23_DEPRECATED
aligned_storage
{
struct type
{
alignas(_Align) unsigned char __data[_Len];
};
};
template <typename... _Types>
struct __strictest_alignment
{
static const size_t _S_alignment = 0;
static const size_t _S_size = 0;
};
template <typename _Tp, typename... _Types>
struct __strictest_alignment<_Tp, _Types...>
{
static const size_t _S_alignment =
alignof(_Tp) > __strictest_alignment<_Types...>::_S_alignment
? alignof(_Tp) : __strictest_alignment<_Types...>::_S_alignment;
static const size_t _S_size =
sizeof(_Tp) > __strictest_alignment<_Types...>::_S_size
? sizeof(_Tp) : __strictest_alignment<_Types...>::_S_size;
};
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
/**
* @brief Provide aligned storage for types.
*
* [meta.trans.other]
*
* Provides aligned storage for any of the provided types of at
* least size _Len.
*
* @see aligned_storage
*
* @deprecated Deprecated in C++23.
*/
template <size_t _Len, typename... _Types>
struct
_GLIBCXX23_DEPRECATED
aligned_union
{
private:
static_assert(sizeof...(_Types) != 0, "At least one type is required");
using __strictest = __strictest_alignment<_Types...>;
static const size_t _S_len = _Len > __strictest::_S_size
? _Len : __strictest::_S_size;
public:
/// The value of the strictest alignment of _Types.
static const size_t alignment_value = __strictest::_S_alignment;
/// The storage.
using type = typename aligned_storage<_S_len, alignment_value>::type;
};
template <size_t _Len, typename... _Types>
const size_t aligned_union<_Len, _Types...>::alignment_value;
#pragma GCC diagnostic pop
// Decay trait for arrays and functions, used for perfect forwarding
// in make_pair, make_tuple, etc.
#if _GLIBCXX_USE_BUILTIN_TRAIT(__decay)
template<typename _Tp>
struct decay
{ using type = __decay(_Tp); };
#else
/// @cond undocumented
template<typename _Up>
struct __decay_selector
: __conditional_t<is_const<const _Up>::value, // false for functions
remove_cv<_Up>, // N.B. DR 705.
add_pointer<_Up>> // function decays to pointer
{ };
template<typename _Up, size_t _Nm>
struct __decay_selector<_Up[_Nm]>
{ using type = _Up*; };
template<typename _Up>
struct __decay_selector<_Up[]>
{ using type = _Up*; };
/// @endcond
/// decay
template<typename _Tp>
struct decay
{ using type = typename __decay_selector<_Tp>::type; };
template<typename _Tp>
struct decay<_Tp&>
{ using type = typename __decay_selector<_Tp>::type; };
template<typename _Tp>
struct decay<_Tp&&>
{ using type = typename __decay_selector<_Tp>::type; };
#endif
/// @cond undocumented
// Helper which adds a reference to a type when given a reference_wrapper
template<typename _Tp>
struct __strip_reference_wrapper
{
using __type = _Tp;
};
template<typename _Tp>
struct __strip_reference_wrapper<reference_wrapper<_Tp> >
{
using __type = _Tp&;
};
// __decay_t (std::decay_t for C++11).
template<typename _Tp>
using __decay_t = typename decay<_Tp>::type;
template<typename _Tp>
using __decay_and_strip = __strip_reference_wrapper<__decay_t<_Tp>>;
/// @endcond
/// @cond undocumented
// Helper for SFINAE constraints
template<typename... _Cond>
using _Require = __enable_if_t<__and_<_Cond...>::value>;
// __remove_cvref_t (std::remove_cvref_t for C++11).
template<typename _Tp>
using __remove_cvref_t
= typename remove_cv<typename remove_reference<_Tp>::type>::type;
/// @endcond
// Primary template.
/// Define a member typedef @c type to one of two argument types.
template<bool _Cond, typename _Iftrue, typename _Iffalse>
struct conditional
{ using type = _Iftrue; };
// Partial specialization for false.
template<typename _Iftrue, typename _Iffalse>
struct conditional<false, _Iftrue, _Iffalse>
{ using type = _Iffalse; };
/// common_type
template<typename... _Tp>
struct common_type;
// Sfinae-friendly common_type implementation:
/// @cond undocumented
// 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
// that, because we need to derive from them as an implementation detail.
template<typename _Tp>
struct __success_type
{ using type = _Tp; };
struct __failure_type
{ };
struct __do_common_type_impl
{
template<typename _Tp, typename _Up>
using __cond_t
= decltype(true ? std::declval<_Tp>() : std::declval<_Up>());
// if decay_t<decltype(false ? declval<D1>() : declval<D2>())>
// denotes a valid type, let C denote that type.
template<typename _Tp, typename _Up>
static __success_type<__decay_t<__cond_t<_Tp, _Up>>>
_S_test(int);
#if __cplusplus > 201703L
// Otherwise, if COND-RES(CREF(D1), CREF(D2)) denotes a type,
// let C denote the type decay_t<COND-RES(CREF(D1), CREF(D2))>.
template<typename _Tp, typename _Up>
static __success_type<__remove_cvref_t<__cond_t<const _Tp&, const _Up&>>>
_S_test_2(int);
#endif
template<typename, typename>
static __failure_type
_S_test_2(...);
template<typename _Tp, typename _Up>
static decltype(_S_test_2<_Tp, _Up>(0))
_S_test(...);
};
// If sizeof...(T) is zero, there shall be no member type.
template<>
struct common_type<>
{ };
// If sizeof...(T) is one, the same type, if any, as common_type_t<T0, T0>.
template<typename _Tp0>
struct common_type<_Tp0>
: public common_type<_Tp0, _Tp0>
{ };
// If sizeof...(T) is two, ...
template<typename _Tp1, typename _Tp2,
typename _Dp1 = __decay_t<_Tp1>, typename _Dp2 = __decay_t<_Tp2>>
struct __common_type_impl
{
// If is_same_v<T1, D1> is false or is_same_v<T2, D2> is false,
// let C denote the same type, if any, as common_type_t<D1, D2>.
using type = common_type<_Dp1, _Dp2>;
};
template<typename _Tp1, typename _Tp2>
struct __common_type_impl<_Tp1, _Tp2, _Tp1, _Tp2>
: private __do_common_type_impl
{
// Otherwise, if decay_t<decltype(false ? declval<D1>() : declval<D2>())>
// denotes a valid type, let C denote that type.
using type = decltype(_S_test<_Tp1, _Tp2>(0));
};
// If sizeof...(T) is two, ...
template<typename _Tp1, typename _Tp2>
struct common_type<_Tp1, _Tp2>
: public __common_type_impl<_Tp1, _Tp2>::type
{ };
template<typename...>
struct __common_type_pack
{ };
template<typename, typename, typename = void>
struct __common_type_fold;
// If sizeof...(T) is greater than two, ...
template<typename _Tp1, typename _Tp2, typename... _Rp>
struct common_type<_Tp1, _Tp2, _Rp...>
: public __common_type_fold<common_type<_Tp1, _Tp2>,
__common_type_pack<_Rp...>>
{ };
// Let C denote the same type, if any, as common_type_t<T1, T2>.
// If there is such a type C, type shall denote the same type, if any,
// as common_type_t<C, R...>.
template<typename _CTp, typename... _Rp>
struct __common_type_fold<_CTp, __common_type_pack<_Rp...>,
__void_t<typename _CTp::type>>
: public common_type<typename _CTp::type, _Rp...>
{ };
// Otherwise, there shall be no member type.
template<typename _CTp, typename _Rp>
struct __common_type_fold<_CTp, _Rp, void>
{ };
template<typename _Tp, bool = __is_enum(_Tp)>
struct __underlying_type_impl
{
using type = __underlying_type(_Tp);
};
template<typename _Tp>
struct __underlying_type_impl<_Tp, false>
{ };
/// @endcond
/// The underlying type of an enum.
template<typename _Tp>
struct underlying_type
: public __underlying_type_impl<_Tp>
{ };
/// @cond undocumented
template<typename _Tp>
struct __declval_protector
{
static const bool __stop = false;
};
/// @endcond
/** Utility to simplify expressions used in unevaluated operands
* @since C++11
* @ingroup utilities
*/
template<typename _Tp>
auto declval() noexcept -> decltype(__declval<_Tp>(0))
{
static_assert(__declval_protector<_Tp>::__stop,
"declval() must not be used!");
return __declval<_Tp>(0);
}
/// result_of
template<typename _Signature>
struct result_of;
// Sfinae-friendly result_of implementation:
/// @cond undocumented
struct __invoke_memfun_ref { };
struct __invoke_memfun_deref { };
struct __invoke_memobj_ref { };
struct __invoke_memobj_deref { };
struct __invoke_other { };
// Associate a tag type with a specialization of __success_type.
template<typename _Tp, typename _Tag>
struct __result_of_success : __success_type<_Tp>
{ using __invoke_type = _Tag; };
// [func.require] paragraph 1 bullet 1:
struct __result_of_memfun_ref_impl
{
template<typename _Fp, typename _Tp1, typename... _Args>
static __result_of_success<decltype(
(std::declval<_Tp1>().*std::declval<_Fp>())(std::declval<_Args>()...)
), __invoke_memfun_ref> _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
{
using type = decltype(_S_test<_MemPtr, _Arg, _Args...>(0));
};
// [func.require] paragraph 1 bullet 2:
struct __result_of_memfun_deref_impl
{
template<typename _Fp, typename _Tp1, typename... _Args>
static __result_of_success<decltype(
((*std::declval<_Tp1>()).*std::declval<_Fp>())(std::declval<_Args>()...)
), __invoke_memfun_deref> _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
{
using type = decltype(_S_test<_MemPtr, _Arg, _Args...>(0));
};
// [func.require] paragraph 1 bullet 3:
struct __result_of_memobj_ref_impl
{
template<typename _Fp, typename _Tp1>
static __result_of_success<decltype(
std::declval<_Tp1>().*std::declval<_Fp>()
), __invoke_memobj_ref> _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
{
using type = decltype(_S_test<_MemPtr, _Arg>(0));
};
// [func.require] paragraph 1 bullet 4:
struct __result_of_memobj_deref_impl
{
template<typename _Fp, typename _Tp1>
static __result_of_success<decltype(
(*std::declval<_Tp1>()).*std::declval<_Fp>()
), __invoke_memobj_deref> _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
{
using type = decltype(_S_test<_MemPtr, _Arg>(0));
};
template<typename _MemPtr, typename _Arg>
struct __result_of_memobj;
template<typename _Res, typename _Class, typename _Arg>
struct __result_of_memobj<_Res _Class::*, _Arg>
{
using _Argval = __remove_cvref_t<_Arg>;
using _MemPtr = _Res _Class::*;
using type = typename __conditional_t<__or_<is_same<_Argval, _Class>,
is_base_of<_Class, _Argval>>::value,
__result_of_memobj_ref<_MemPtr, _Arg>,
__result_of_memobj_deref<_MemPtr, _Arg>
>::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...>
{
using _Argval = typename remove_reference<_Arg>::type;
using _MemPtr = _Res _Class::*;
using type = typename __conditional_t<is_base_of<_Class, _Argval>::value,
__result_of_memfun_ref<_MemPtr, _Arg, _Args...>,
__result_of_memfun_deref<_MemPtr, _Arg, _Args...>
>::type;
};
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2219. INVOKE-ing a pointer to member with a reference_wrapper
// as the object expression
// Used by result_of, invoke etc. to unwrap a reference_wrapper.
template<typename _Tp, typename _Up = __remove_cvref_t<_Tp>>
struct __inv_unwrap
{
using type = _Tp;
};
template<typename _Tp, typename _Up>
struct __inv_unwrap<_Tp, reference_wrapper<_Up>>
{
using type = _Up&;
};
template<bool, bool, typename _Functor, typename... _ArgTypes>
struct __result_of_impl
{
using type = __failure_type;
};
template<typename _MemPtr, typename _Arg>
struct __result_of_impl<true, false, _MemPtr, _Arg>
: public __result_of_memobj<__decay_t<_MemPtr>,
typename __inv_unwrap<_Arg>::type>
{ };
template<typename _MemPtr, typename _Arg, typename... _Args>
struct __result_of_impl<false, true, _MemPtr, _Arg, _Args...>
: public __result_of_memfun<__decay_t<_MemPtr>,
typename __inv_unwrap<_Arg>::type, _Args...>
{ };
// [func.require] paragraph 1 bullet 5:
struct __result_of_other_impl
{
template<typename _Fn, typename... _Args>
static __result_of_success<decltype(
std::declval<_Fn>()(std::declval<_Args>()...)
), __invoke_other> _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
{
using type = decltype(_S_test<_Functor, _ArgTypes...>(0));
};
// __invoke_result (std::invoke_result for C++11)
template<typename _Functor, typename... _ArgTypes>
struct __invoke_result
: 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
{ };
// __invoke_result_t (std::invoke_result_t for C++11)
template<typename _Fn, typename... _Args>
using __invoke_result_t = typename __invoke_result<_Fn, _Args...>::type;
/// @endcond
template<typename _Functor, typename... _ArgTypes>
struct result_of<_Functor(_ArgTypes...)>
: public __invoke_result<_Functor, _ArgTypes...>
{ } _GLIBCXX17_DEPRECATED_SUGGEST("std::invoke_result");
#if __cplusplus >= 201402L
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
/// Alias template for aligned_storage
template<size_t _Len,
size_t _Align = __aligned_storage_default_alignment(_Len)>
using aligned_storage_t _GLIBCXX23_DEPRECATED = typename aligned_storage<_Len, _Align>::type;
template <size_t _Len, typename... _Types>
using aligned_union_t _GLIBCXX23_DEPRECATED = typename aligned_union<_Len, _Types...>::type;
#pragma GCC diagnostic pop
/// Alias template for decay
template<typename _Tp>
using decay_t = typename decay<_Tp>::type;
/// Alias template for enable_if
template<bool _Cond, typename _Tp = void>
using enable_if_t = typename enable_if<_Cond, _Tp>::type;
/// Alias template for conditional
template<bool _Cond, typename _Iftrue, typename _Iffalse>
using conditional_t = typename conditional<_Cond, _Iftrue, _Iffalse>::type;
/// Alias template for common_type
template<typename... _Tp>
using common_type_t = typename common_type<_Tp...>::type;
/// Alias template for underlying_type
template<typename _Tp>
using underlying_type_t = typename underlying_type<_Tp>::type;
/// Alias template for result_of
template<typename _Tp>
using result_of_t = typename result_of<_Tp>::type;
#endif // C++14
#ifdef __cpp_lib_void_t // C++ >= 17 || GNU++ >= 11
/// A metafunction that always yields void, used for detecting valid types.
template<typename...> using void_t = void;
#endif
/// @cond undocumented
// Detection idiom.
// Detect whether _Op<_Args...> is a valid type, use default _Def if not.
#if __cpp_concepts
// Implementation of the detection idiom (negative case).
template<typename _Def, template<typename...> class _Op, typename... _Args>
struct __detected_or
{
using type = _Def;
using __is_detected = false_type;
};
// Implementation of the detection idiom (positive case).
template<typename _Def, template<typename...> class _Op, typename... _Args>
requires requires { typename _Op<_Args...>; }
struct __detected_or<_Def, _Op, _Args...>
{
using type = _Op<_Args...>;
using __is_detected = true_type;
};
#else
/// Implementation of the detection idiom (negative case).
template<typename _Default, typename _AlwaysVoid,
template<typename...> class _Op, typename... _Args>
struct __detector
{
using type = _Default;
using __is_detected = false_type;
};
/// Implementation of the detection idiom (positive case).
template<typename _Default, template<typename...> class _Op,
typename... _Args>
struct __detector<_Default, __void_t<_Op<_Args...>>, _Op, _Args...>
{
using type = _Op<_Args...>;
using __is_detected = true_type;
};
template<typename _Default, template<typename...> class _Op,
typename... _Args>
using __detected_or = __detector<_Default, void, _Op, _Args...>;
#endif // __cpp_concepts
// _Op<_Args...> if that is a valid type, otherwise _Default.
template<typename _Default, template<typename...> class _Op,
typename... _Args>
using __detected_or_t
= typename __detected_or<_Default, _Op, _Args...>::type;
/**
* Use SFINAE to determine if the type _Tp has a publicly-accessible
* member type _NTYPE.
*/
#define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE) \
template<typename _Tp, typename = __void_t<>> \
struct __has_##_NTYPE \
: false_type \
{ }; \
template<typename _Tp> \
struct __has_##_NTYPE<_Tp, __void_t<typename _Tp::_NTYPE>> \
: true_type \
{ };
template <typename _Tp>
struct __is_swappable;
template <typename _Tp>
struct __is_nothrow_swappable;
template<typename>
struct __is_tuple_like_impl : false_type
{ };
// Internal type trait that allows us to sfinae-protect tuple_cat.
template<typename _Tp>
struct __is_tuple_like
: public __is_tuple_like_impl<__remove_cvref_t<_Tp>>::type
{ };
/// @endcond
template<typename _Tp>
_GLIBCXX20_CONSTEXPR
inline
_Require<__not_<__is_tuple_like<_Tp>>,
is_move_constructible<_Tp>,
is_move_assignable<_Tp>>
swap(_Tp&, _Tp&)
noexcept(__and_<is_nothrow_move_constructible<_Tp>,
is_nothrow_move_assignable<_Tp>>::value);
template<typename _Tp, size_t _Nm>
_GLIBCXX20_CONSTEXPR
inline
__enable_if_t<__is_swappable<_Tp>::value>
swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
noexcept(__is_nothrow_swappable<_Tp>::value);
/// @cond undocumented
namespace __swappable_details {
using std::swap;
struct __do_is_swappable_impl
{
template<typename _Tp, typename
= decltype(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))>
static true_type __test(int);
template<typename>
static false_type __test(...);
};
struct __do_is_nothrow_swappable_impl
{
template<typename _Tp>
static __bool_constant<
noexcept(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))
> __test(int);
template<typename>
static false_type __test(...);
};
} // namespace __swappable_details
template<typename _Tp>
struct __is_swappable_impl
: public __swappable_details::__do_is_swappable_impl
{
using type = decltype(__test<_Tp>(0));
};
template<typename _Tp>
struct __is_nothrow_swappable_impl
: public __swappable_details::__do_is_nothrow_swappable_impl
{
using type = decltype(__test<_Tp>(0));
};
template<typename _Tp>
struct __is_swappable
: public __is_swappable_impl<_Tp>::type
{ };
template<typename _Tp>
struct __is_nothrow_swappable
: public __is_nothrow_swappable_impl<_Tp>::type
{ };
/// @endcond
#ifdef __cpp_lib_is_swappable // C++ >= 17 || GNU++ >= 11
/// Metafunctions used for detecting swappable types: p0185r1
/// is_swappable
template<typename _Tp>
struct is_swappable
: public __is_swappable_impl<_Tp>::type
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
/// is_nothrow_swappable
template<typename _Tp>
struct is_nothrow_swappable
: public __is_nothrow_swappable_impl<_Tp>::type
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
#if __cplusplus >= 201402L
/// is_swappable_v
template<typename _Tp>
_GLIBCXX17_INLINE constexpr bool is_swappable_v =
is_swappable<_Tp>::value;
/// is_nothrow_swappable_v
template<typename _Tp>
_GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_v =
is_nothrow_swappable<_Tp>::value;
#endif // __cplusplus >= 201402L
/// @cond undocumented
namespace __swappable_with_details {
using std::swap;
struct __do_is_swappable_with_impl
{
template<typename _Tp, typename _Up, typename
= decltype(swap(std::declval<_Tp>(), std::declval<_Up>())),
typename
= decltype(swap(std::declval<_Up>(), std::declval<_Tp>()))>
static true_type __test(int);
template<typename, typename>
static false_type __test(...);
};
struct __do_is_nothrow_swappable_with_impl
{
template<typename _Tp, typename _Up>
static __bool_constant<
noexcept(swap(std::declval<_Tp>(), std::declval<_Up>()))
&&
noexcept(swap(std::declval<_Up>(), std::declval<_Tp>()))
> __test(int);
template<typename, typename>
static false_type __test(...);
};
} // namespace __swappable_with_details
template<typename _Tp, typename _Up>
struct __is_swappable_with_impl
: public __swappable_with_details::__do_is_swappable_with_impl
{
using type = decltype(__test<_Tp, _Up>(0));
};
// Optimization for the homogenous lvalue case, not required:
template<typename _Tp>
struct __is_swappable_with_impl<_Tp&, _Tp&>
: public __swappable_details::__do_is_swappable_impl
{
using type = decltype(__test<_Tp&>(0));
};
template<typename _Tp, typename _Up>
struct __is_nothrow_swappable_with_impl
: public __swappable_with_details::__do_is_nothrow_swappable_with_impl
{
using type = decltype(__test<_Tp, _Up>(0));
};
// Optimization for the homogenous lvalue case, not required:
template<typename _Tp>
struct __is_nothrow_swappable_with_impl<_Tp&, _Tp&>
: public __swappable_details::__do_is_nothrow_swappable_impl
{
using type = decltype(__test<_Tp&>(0));
};
/// @endcond
/// is_swappable_with
template<typename _Tp, typename _Up>
struct is_swappable_with
: public __is_swappable_with_impl<_Tp, _Up>::type
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"first template argument must be a complete class or an unbounded array");
static_assert(std::__is_complete_or_unbounded(__type_identity<_Up>{}),
"second template argument must be a complete class or an unbounded array");
};
/// is_nothrow_swappable_with
template<typename _Tp, typename _Up>
struct is_nothrow_swappable_with
: public __is_nothrow_swappable_with_impl<_Tp, _Up>::type
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"first template argument must be a complete class or an unbounded array");
static_assert(std::__is_complete_or_unbounded(__type_identity<_Up>{}),
"second template argument must be a complete class or an unbounded array");
};
#if __cplusplus >= 201402L
/// is_swappable_with_v
template<typename _Tp, typename _Up>
_GLIBCXX17_INLINE constexpr bool is_swappable_with_v =
is_swappable_with<_Tp, _Up>::value;
/// is_nothrow_swappable_with_v
template<typename _Tp, typename _Up>
_GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_with_v =
is_nothrow_swappable_with<_Tp, _Up>::value;
#endif // __cplusplus >= 201402L
#endif // __cpp_lib_is_swappable
/// @cond undocumented
// __is_invocable (std::is_invocable for C++11)
// The primary template is used for invalid INVOKE expressions.
template<typename _Result, typename _Ret,
bool = is_void<_Ret>::value, typename = void>
struct __is_invocable_impl
: false_type
{
using __nothrow_conv = false_type; // For is_nothrow_invocable_r
};
// Used for valid INVOKE and INVOKE<void> expressions.
template<typename _Result, typename _Ret>
struct __is_invocable_impl<_Result, _Ret,
/* is_void<_Ret> = */ true,
__void_t<typename _Result::type>>
: true_type
{
using __nothrow_conv = true_type; // For is_nothrow_invocable_r
};
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
// Used for INVOKE<R> expressions to check the implicit conversion to R.
template<typename _Result, typename _Ret>
struct __is_invocable_impl<_Result, _Ret,
/* is_void<_Ret> = */ false,
__void_t<typename _Result::type>>
{
private:
// The type of the INVOKE expression.
using _Res_t = typename _Result::type;
// Unlike declval, this doesn't add_rvalue_reference, so it respects
// guaranteed copy elision.
static _Res_t _S_get() noexcept;
// Used to check if _Res_t can implicitly convert to _Tp.
template<typename _Tp>
static void _S_conv(__type_identity_t<_Tp>) noexcept;
// This overload is viable if INVOKE(f, args...) can convert to _Tp.
template<typename _Tp,
bool _Nothrow = noexcept(_S_conv<_Tp>(_S_get())),
typename = decltype(_S_conv<_Tp>(_S_get())),
#if __has_builtin(__reference_converts_from_temporary)
bool _Dangle = __reference_converts_from_temporary(_Tp, _Res_t)
#else
bool _Dangle = false
#endif
>
static __bool_constant<_Nothrow && !_Dangle>
_S_test(int);
template<typename _Tp, bool = false>
static false_type
_S_test(...);
public:
// For is_invocable_r
using type = decltype(_S_test<_Ret, /* Nothrow = */ true>(1));
// For is_nothrow_invocable_r
using __nothrow_conv = decltype(_S_test<_Ret>(1));
};
#pragma GCC diagnostic pop
template<typename _Fn, typename... _ArgTypes>
struct __is_invocable
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_invocable)
: __bool_constant<__is_invocable(_Fn, _ArgTypes...)>
#else
: __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
#endif
{ };
template<typename _Fn, typename _Tp, typename... _Args>
constexpr bool __call_is_nt(__invoke_memfun_ref)
{
using _Up = typename __inv_unwrap<_Tp>::type;
return noexcept((std::declval<_Up>().*std::declval<_Fn>())(
std::declval<_Args>()...));
}
template<typename _Fn, typename _Tp, typename... _Args>
constexpr bool __call_is_nt(__invoke_memfun_deref)
{
return noexcept(((*std::declval<_Tp>()).*std::declval<_Fn>())(
std::declval<_Args>()...));
}
template<typename _Fn, typename _Tp>
constexpr bool __call_is_nt(__invoke_memobj_ref)
{
using _Up = typename __inv_unwrap<_Tp>::type;
return noexcept(std::declval<_Up>().*std::declval<_Fn>());
}
template<typename _Fn, typename _Tp>
constexpr bool __call_is_nt(__invoke_memobj_deref)
{
return noexcept((*std::declval<_Tp>()).*std::declval<_Fn>());
}
template<typename _Fn, typename... _Args>
constexpr bool __call_is_nt(__invoke_other)
{
return noexcept(std::declval<_Fn>()(std::declval<_Args>()...));
}
template<typename _Result, typename _Fn, typename... _Args>
struct __call_is_nothrow
: __bool_constant<
std::__call_is_nt<_Fn, _Args...>(typename _Result::__invoke_type{})
>
{ };
template<typename _Fn, typename... _Args>
using __call_is_nothrow_
= __call_is_nothrow<__invoke_result<_Fn, _Args...>, _Fn, _Args...>;
// __is_nothrow_invocable (std::is_nothrow_invocable for C++11)
template<typename _Fn, typename... _Args>
struct __is_nothrow_invocable
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_nothrow_invocable)
: __bool_constant<__is_nothrow_invocable(_Fn, _Args...)>
#else
: __and_<__is_invocable<_Fn, _Args...>,
__call_is_nothrow_<_Fn, _Args...>>::type
#endif
{ };
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
struct __nonesuchbase {};
struct __nonesuch : private __nonesuchbase {
~__nonesuch() = delete;
__nonesuch(__nonesuch const&) = delete;
void operator=(__nonesuch const&) = delete;
};
#pragma GCC diagnostic pop
/// @endcond
#ifdef __cpp_lib_is_invocable // C++ >= 17
/// std::invoke_result
template<typename _Functor, typename... _ArgTypes>
struct invoke_result
: public __invoke_result<_Functor, _ArgTypes...>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Functor>{}),
"_Functor must be a complete class or an unbounded array");
static_assert((std::__is_complete_or_unbounded(
__type_identity<_ArgTypes>{}) && ...),
"each argument type must be a complete class or an unbounded array");
};
/// std::invoke_result_t
template<typename _Fn, typename... _Args>
using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
/// std::is_invocable
template<typename _Fn, typename... _ArgTypes>
struct is_invocable
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_invocable)
: public __bool_constant<__is_invocable(_Fn, _ArgTypes...)>
#else
: __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
#endif
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
"_Fn must be a complete class or an unbounded array");
static_assert((std::__is_complete_or_unbounded(
__type_identity<_ArgTypes>{}) && ...),
"each argument type must be a complete class or an unbounded array");
};
/// std::is_invocable_r
template<typename _Ret, typename _Fn, typename... _ArgTypes>
struct is_invocable_r
: __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>::type
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
"_Fn must be a complete class or an unbounded array");
static_assert((std::__is_complete_or_unbounded(
__type_identity<_ArgTypes>{}) && ...),
"each argument type must be a complete class or an unbounded array");
static_assert(std::__is_complete_or_unbounded(__type_identity<_Ret>{}),
"_Ret must be a complete class or an unbounded array");
};
/// std::is_nothrow_invocable
template<typename _Fn, typename... _ArgTypes>
struct is_nothrow_invocable
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_nothrow_invocable)
: public __bool_constant<__is_nothrow_invocable(_Fn, _ArgTypes...)>
#else
: __and_<__is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>,
__call_is_nothrow_<_Fn, _ArgTypes...>>::type
#endif
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
"_Fn must be a complete class or an unbounded array");
static_assert((std::__is_complete_or_unbounded(
__type_identity<_ArgTypes>{}) && ...),
"each argument type must be a complete class or an unbounded array");
};
/// @cond undocumented
// This checks that the INVOKE<R> expression is well-formed and that the
// conversion to R does not throw. It does *not* check whether the INVOKE
// expression itself can throw. That is done by __call_is_nothrow_ instead.
template<typename _Result, typename _Ret>
using __is_nt_invocable_impl
= typename __is_invocable_impl<_Result, _Ret>::__nothrow_conv;
/// @endcond
/// std::is_nothrow_invocable_r
template<typename _Ret, typename _Fn, typename... _ArgTypes>
struct is_nothrow_invocable_r
: __and_<__is_nt_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>,
__call_is_nothrow_<_Fn, _ArgTypes...>>::type
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
"_Fn must be a complete class or an unbounded array");
static_assert((std::__is_complete_or_unbounded(
__type_identity<_ArgTypes>{}) && ...),
"each argument type must be a complete class or an unbounded array");
static_assert(std::__is_complete_or_unbounded(__type_identity<_Ret>{}),
"_Ret must be a complete class or an unbounded array");
};
#endif // __cpp_lib_is_invocable
#if __cpp_lib_type_trait_variable_templates // C++ >= 17
/**
* @defgroup variable_templates Variable templates for type traits
* @ingroup metaprogramming
*
* Each variable `is_xxx_v<T>` is a boolean constant with the same value
* as the `value` member of the corresponding type trait `is_xxx<T>`.
*
* @since C++17 unless noted otherwise.
*/
/**
* @{
* @ingroup variable_templates
*/
template <typename _Tp>
inline constexpr bool is_void_v = is_void<_Tp>::value;
template <typename _Tp>
inline constexpr bool is_null_pointer_v = is_null_pointer<_Tp>::value;
template <typename _Tp>
inline constexpr bool is_integral_v = is_integral<_Tp>::value;
template <typename _Tp>
inline constexpr bool is_floating_point_v = is_floating_point<_Tp>::value;
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_array)
template <typename _Tp>
inline constexpr bool is_array_v = __is_array(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_array_v = false;
template <typename _Tp>
inline constexpr bool is_array_v<_Tp[]> = true;
template <typename _Tp, size_t _Num>
inline constexpr bool is_array_v<_Tp[_Num]> = true;
#endif
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer)
template <typename _Tp>
inline constexpr bool is_pointer_v = __is_pointer(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_pointer_v = false;
template <typename _Tp>
inline constexpr bool is_pointer_v<_Tp*> = true;
template <typename _Tp>
inline constexpr bool is_pointer_v<_Tp* const> = true;
template <typename _Tp>
inline constexpr bool is_pointer_v<_Tp* volatile> = true;
template <typename _Tp>
inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
#endif
template <typename _Tp>
inline constexpr bool is_lvalue_reference_v = false;
template <typename _Tp>
inline constexpr bool is_lvalue_reference_v<_Tp&> = true;
template <typename _Tp>
inline constexpr bool is_rvalue_reference_v = false;
template <typename _Tp>
inline constexpr bool is_rvalue_reference_v<_Tp&&> = true;
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_member_object_pointer)
template <typename _Tp>
inline constexpr bool is_member_object_pointer_v =
__is_member_object_pointer(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_member_object_pointer_v =
is_member_object_pointer<_Tp>::value;
#endif
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_member_function_pointer)
template <typename _Tp>
inline constexpr bool is_member_function_pointer_v =
__is_member_function_pointer(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_member_function_pointer_v =
is_member_function_pointer<_Tp>::value;
#endif
#if __cpp_impl_reflection >= 202506L // C++ >= 26
template <typename _Tp>
inline constexpr bool is_reflection_v = false;
template <>
inline constexpr bool is_reflection_v<decltype(^^int)> = true;
template <>
inline constexpr bool is_reflection_v<const decltype(^^int)> = true;
template <>
inline constexpr bool is_reflection_v<volatile decltype(^^int)> = true;
template <>
inline constexpr bool is_reflection_v<const volatile decltype(^^int)> = true;
#endif
template <typename _Tp>
inline constexpr bool is_enum_v = __is_enum(_Tp);
template <typename _Tp>
inline constexpr bool is_union_v = __is_union(_Tp);
template <typename _Tp>
inline constexpr bool is_class_v = __is_class(_Tp);
// is_function_v is defined below, after is_const_v.
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_reference)
template <typename _Tp>
inline constexpr bool is_reference_v = __is_reference(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_reference_v = false;
template <typename _Tp>
inline constexpr bool is_reference_v<_Tp&> = true;
template <typename _Tp>
inline constexpr bool is_reference_v<_Tp&&> = true;
#endif
template <typename _Tp>
inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
template <typename _Tp>
inline constexpr bool is_fundamental_v = is_fundamental<_Tp>::value;
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_object)
template <typename _Tp>
inline constexpr bool is_object_v = __is_object(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_object_v = is_object<_Tp>::value;
#endif
template <typename _Tp>
inline constexpr bool is_scalar_v = is_scalar<_Tp>::value;
template <typename _Tp>
inline constexpr bool is_compound_v = !is_fundamental_v<_Tp>;
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_member_pointer)
template <typename _Tp>
inline constexpr bool is_member_pointer_v = __is_member_pointer(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_member_pointer_v = is_member_pointer<_Tp>::value;
#endif
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_const)
template <typename _Tp>
inline constexpr bool is_const_v = __is_const(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_const_v = false;
template <typename _Tp>
inline constexpr bool is_const_v<const _Tp> = true;
#endif
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_function)
template <typename _Tp>
inline constexpr bool is_function_v = __is_function(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_function_v = !is_const_v<const _Tp>;
template <typename _Tp>
inline constexpr bool is_function_v<_Tp&> = false;
template <typename _Tp>
inline constexpr bool is_function_v<_Tp&&> = false;
#endif
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_volatile)
template <typename _Tp>
inline constexpr bool is_volatile_v = __is_volatile(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_volatile_v = false;
template <typename _Tp>
inline constexpr bool is_volatile_v<volatile _Tp> = true;
#endif
template <typename _Tp>
_GLIBCXX26_DEPRECATED_SUGGEST("is_trivially_default_constructible_v && is_trivially_copyable_v")
inline constexpr bool is_trivial_v = __is_trivial(_Tp);
template <typename _Tp>
inline constexpr bool is_trivially_copyable_v = __is_trivially_copyable(_Tp);
template <typename _Tp>
inline constexpr bool is_standard_layout_v = __is_standard_layout(_Tp);
template <typename _Tp>
_GLIBCXX20_DEPRECATED_SUGGEST("is_standard_layout_v && is_trivial_v")
inline constexpr bool is_pod_v = __is_pod(_Tp);
template <typename _Tp>
_GLIBCXX17_DEPRECATED
inline constexpr bool is_literal_type_v = __is_literal_type(_Tp);
template <typename _Tp>
inline constexpr bool is_empty_v = __is_empty(_Tp);
template <typename _Tp>
inline constexpr bool is_polymorphic_v = __is_polymorphic(_Tp);
template <typename _Tp>
inline constexpr bool is_abstract_v = __is_abstract(_Tp);
template <typename _Tp>
inline constexpr bool is_final_v = __is_final(_Tp);
template <typename _Tp>
inline constexpr bool is_signed_v = is_signed<_Tp>::value;
template <typename _Tp>
inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;
template <typename _Tp, typename... _Args>
inline constexpr bool is_constructible_v = __is_constructible(_Tp, _Args...);
template <typename _Tp>
inline constexpr bool is_default_constructible_v = __is_constructible(_Tp);
template <typename _Tp>
inline constexpr bool is_copy_constructible_v
= __is_constructible(_Tp, __add_lval_ref_t<const _Tp>);
template <typename _Tp>
inline constexpr bool is_move_constructible_v
= __is_constructible(_Tp, __add_rval_ref_t<_Tp>);
template <typename _Tp, typename _Up>
inline constexpr bool is_assignable_v = __is_assignable(_Tp, _Up);
template <typename _Tp>
inline constexpr bool is_copy_assignable_v
= __is_assignable(__add_lval_ref_t<_Tp>, __add_lval_ref_t<const _Tp>);
template <typename _Tp>
inline constexpr bool is_move_assignable_v
= __is_assignable(__add_lval_ref_t<_Tp>, __add_rval_ref_t<_Tp>);
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_destructible)
template <typename _Tp>
inline constexpr bool is_destructible_v = __is_destructible(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_destructible_v = is_destructible<_Tp>::value;
#endif
template <typename _Tp, typename... _Args>
inline constexpr bool is_trivially_constructible_v
= __is_trivially_constructible(_Tp, _Args...);
template <typename _Tp>
inline constexpr bool is_trivially_default_constructible_v
= __is_trivially_constructible(_Tp);
template <typename _Tp>
inline constexpr bool is_trivially_copy_constructible_v
= __is_trivially_constructible(_Tp, __add_lval_ref_t<const _Tp>);
template <typename _Tp>
inline constexpr bool is_trivially_move_constructible_v
= __is_trivially_constructible(_Tp, __add_rval_ref_t<_Tp>);
template <typename _Tp, typename _Up>
inline constexpr bool is_trivially_assignable_v
= __is_trivially_assignable(_Tp, _Up);
template <typename _Tp>
inline constexpr bool is_trivially_copy_assignable_v
= __is_trivially_assignable(__add_lval_ref_t<_Tp>,
__add_lval_ref_t<const _Tp>);
template <typename _Tp>
inline constexpr bool is_trivially_move_assignable_v
= __is_trivially_assignable(__add_lval_ref_t<_Tp>,
__add_rval_ref_t<_Tp>);
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_trivially_destructible)
template <typename _Tp>
inline constexpr bool is_trivially_destructible_v
= __is_trivially_destructible(_Tp);
#elif __cpp_concepts
template <typename _Tp>
inline constexpr bool is_trivially_destructible_v = false;
template <typename _Tp>
requires (!is_reference_v<_Tp>) && requires (_Tp& __t) { __t.~_Tp(); }
inline constexpr bool is_trivially_destructible_v<_Tp>
= __has_trivial_destructor(_Tp);
template <typename _Tp>
inline constexpr bool is_trivially_destructible_v<_Tp&> = true;
template <typename _Tp>
inline constexpr bool is_trivially_destructible_v<_Tp&&> = true;
template <typename _Tp, size_t _Nm>
inline constexpr bool is_trivially_destructible_v<_Tp[_Nm]>
= is_trivially_destructible_v<_Tp>;
#else
template <typename _Tp>
inline constexpr bool is_trivially_destructible_v =
is_trivially_destructible<_Tp>::value;
#endif
template <typename _Tp, typename... _Args>
inline constexpr bool is_nothrow_constructible_v
= __is_nothrow_constructible(_Tp, _Args...);
template <typename _Tp>
inline constexpr bool is_nothrow_default_constructible_v
= __is_nothrow_constructible(_Tp);
template <typename _Tp>
inline constexpr bool is_nothrow_copy_constructible_v
= __is_nothrow_constructible(_Tp, __add_lval_ref_t<const _Tp>);
template <typename _Tp>
inline constexpr bool is_nothrow_move_constructible_v
= __is_nothrow_constructible(_Tp, __add_rval_ref_t<_Tp>);
template <typename _Tp, typename _Up>
inline constexpr bool is_nothrow_assignable_v
= __is_nothrow_assignable(_Tp, _Up);
template <typename _Tp>
inline constexpr bool is_nothrow_copy_assignable_v
= __is_nothrow_assignable(__add_lval_ref_t<_Tp>,
__add_lval_ref_t<const _Tp>);
template <typename _Tp>
inline constexpr bool is_nothrow_move_assignable_v
= __is_nothrow_assignable(__add_lval_ref_t<_Tp>, __add_rval_ref_t<_Tp>);
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_nothrow_destructible)
template <typename _Tp>
inline constexpr bool is_nothrow_destructible_v
= __is_nothrow_destructible(_Tp);
#else
template <typename _Tp>
inline constexpr bool is_nothrow_destructible_v =
is_nothrow_destructible<_Tp>::value;
#endif
template <typename _Tp>
inline constexpr bool has_virtual_destructor_v
= __has_virtual_destructor(_Tp);
template <typename _Tp>
inline constexpr size_t alignment_of_v = alignment_of<_Tp>::value;
#if _GLIBCXX_USE_BUILTIN_TRAIT(__array_rank) \
&& (!defined(__clang__) || __clang_major__ >= 20) // PR118559
template <typename _Tp>
inline constexpr size_t rank_v = __array_rank(_Tp);
#else
template <typename _Tp>
inline constexpr size_t rank_v = 0;
template <typename _Tp, size_t _Size>
inline constexpr size_t rank_v<_Tp[_Size]> = 1 + rank_v<_Tp>;
template <typename _Tp>
inline constexpr size_t rank_v<_Tp[]> = 1 + rank_v<_Tp>;
#endif
template <typename _Tp, unsigned _Idx = 0>
inline constexpr size_t extent_v = 0;
template <typename _Tp, size_t _Size>
inline constexpr size_t extent_v<_Tp[_Size], 0> = _Size;
template <typename _Tp, unsigned _Idx, size_t _Size>
inline constexpr size_t extent_v<_Tp[_Size], _Idx> = extent_v<_Tp, _Idx - 1>;
template <typename _Tp>
inline constexpr size_t extent_v<_Tp[], 0> = 0;
template <typename _Tp, unsigned _Idx>
inline constexpr size_t extent_v<_Tp[], _Idx> = extent_v<_Tp, _Idx - 1>;
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_same)
template <typename _Tp, typename _Up>
inline constexpr bool is_same_v = __is_same(_Tp, _Up);
#else
template <typename _Tp, typename _Up>
inline constexpr bool is_same_v = false;
template <typename _Tp>
inline constexpr bool is_same_v<_Tp, _Tp> = true;
#endif
template <typename _Base, typename _Derived>
inline constexpr bool is_base_of_v = __is_base_of(_Base, _Derived);
#ifdef __cpp_lib_is_virtual_base_of // C++ >= 26
template <typename _Base, typename _Derived>
inline constexpr bool is_virtual_base_of_v = __builtin_is_virtual_base_of(_Base, _Derived);
#endif
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_convertible)
template <typename _From, typename _To>
inline constexpr bool is_convertible_v = __is_convertible(_From, _To);
#else
template <typename _From, typename _To>
inline constexpr bool is_convertible_v = is_convertible<_From, _To>::value;
#endif
template<typename _Fn, typename... _Args>
inline constexpr bool is_invocable_v
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_invocable)
= __is_invocable(_Fn, _Args...);
#else
= is_invocable<_Fn, _Args...>::value;
#endif
template<typename _Fn, typename... _Args>
inline constexpr bool is_nothrow_invocable_v
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_nothrow_invocable)
= __is_nothrow_invocable(_Fn, _Args...);
#else
= is_nothrow_invocable<_Fn, _Args...>::value;
#endif
template<typename _Ret, typename _Fn, typename... _Args>
inline constexpr bool is_invocable_r_v
= is_invocable_r<_Ret, _Fn, _Args...>::value;
template<typename _Ret, typename _Fn, typename... _Args>
inline constexpr bool is_nothrow_invocable_r_v
= is_nothrow_invocable_r<_Ret, _Fn, _Args...>::value;
/// @}
#endif // __cpp_lib_type_trait_variable_templates
#ifdef __cpp_lib_has_unique_object_representations // C++ >= 17 && HAS_UNIQ_OBJ_REP
/// has_unique_object_representations
/// @since C++17
template<typename _Tp>
struct has_unique_object_representations
: bool_constant<__has_unique_object_representations(
remove_cv_t<remove_all_extents_t<_Tp>>
)>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
"template argument must be a complete class or an unbounded array");
};
# if __cpp_lib_type_trait_variable_templates // C++ >= 17
/// @ingroup variable_templates
template<typename _Tp>
inline constexpr bool has_unique_object_representations_v
= has_unique_object_representations<_Tp>::value;
# endif
#endif
#ifdef __cpp_lib_is_aggregate // C++ >= 17 && builtin_is_aggregate
/// is_aggregate - true if the type is an aggregate.
/// @since C++17
template<typename _Tp>
struct is_aggregate
: bool_constant<__is_aggregate(remove_cv_t<_Tp>)>
{ };
# if __cpp_lib_type_trait_variable_templates // C++ >= 17
/** is_aggregate_v - true if the type is an aggregate.
* @ingroup variable_templates
* @since C++17
*/
template<typename _Tp>
inline constexpr bool is_aggregate_v = __is_aggregate(remove_cv_t<_Tp>);
# endif
#endif
#if __cpp_lib_is_structural >= 202603L // C++ >= 26
/// is_structural - true if the type is a structural type.
/// @since C++26
template<typename _Tp>
struct is_structural
: bool_constant<__builtin_is_structural(_Tp)>
{ };
/** is_structural_v - true if the type is a structural only type.
* @ingroup variable_templates
* @since C++26
*/
template<typename _Tp>
inline constexpr bool is_structural_v
= __builtin_is_structural(_Tp);
#endif
/** * Remove references and cv-qualifiers.
* @since C++20
* @{
*/
#ifdef __cpp_lib_remove_cvref // C++ >= 20
# if _GLIBCXX_USE_BUILTIN_TRAIT(__remove_cvref)
template<typename _Tp>
struct remove_cvref
{ using type = __remove_cvref(_Tp); };
# else
template<typename _Tp>
struct remove_cvref
{ using type = typename remove_cv<_Tp>::type; };
template<typename _Tp>
struct remove_cvref<_Tp&>
{ using type = typename remove_cv<_Tp>::type; };
template<typename _Tp>
struct remove_cvref<_Tp&&>
{ using type = typename remove_cv<_Tp>::type; };
# endif
template<typename _Tp>
using remove_cvref_t = typename remove_cvref<_Tp>::type;
/// @}
#endif // __cpp_lib_remove_cvref
#ifdef __cpp_lib_type_identity // C++ >= 20
/** * Identity metafunction.
* @since C++20
* @{
*/
template<typename _Tp>
struct type_identity { using type = _Tp; };
template<typename _Tp>
using type_identity_t = typename type_identity<_Tp>::type;
/// @}
#endif
#ifdef __cpp_lib_unwrap_ref // C++ >= 20
/** Unwrap a reference_wrapper
* @since C++20
* @{
*/
template<typename _Tp>
struct unwrap_reference { using type = _Tp; };
template<typename _Tp>
struct unwrap_reference<reference_wrapper<_Tp>> { using type = _Tp&; };
template<typename _Tp>
using unwrap_reference_t = typename unwrap_reference<_Tp>::type;
/// @}
/** Decay type and if it's a reference_wrapper, unwrap it
* @since C++20
* @{
*/
template<typename _Tp>
struct unwrap_ref_decay { using type = unwrap_reference_t<decay_t<_Tp>>; };
template<typename _Tp>
using unwrap_ref_decay_t = typename unwrap_ref_decay<_Tp>::type;
/// @}
#endif // __cpp_lib_unwrap_ref
#ifdef __cpp_lib_bounded_array_traits // C++ >= 20
/// True for a type that is an array of known bound.
/// @ingroup variable_templates
/// @since C++20
# if _GLIBCXX_USE_BUILTIN_TRAIT(__is_bounded_array)
template<typename _Tp>
inline constexpr bool is_bounded_array_v = __is_bounded_array(_Tp);
# else
template<typename _Tp>
inline constexpr bool is_bounded_array_v = false;
template<typename _Tp, size_t _Size>
inline constexpr bool is_bounded_array_v<_Tp[_Size]> = true;
# endif
/// True for a type that is an array of unknown bound.
/// @ingroup variable_templates
/// @since C++20
# if _GLIBCXX_USE_BUILTIN_TRAIT(__is_unbounded_array)
template<typename _Tp>
inline constexpr bool is_unbounded_array_v = __is_unbounded_array(_Tp);
# else
template<typename _Tp>
inline constexpr bool is_unbounded_array_v = false;
template<typename _Tp>
inline constexpr bool is_unbounded_array_v<_Tp[]> = true;
# endif
/// True for a type that is an array of known bound.
/// @since C++20
template<typename _Tp>
struct is_bounded_array
: public bool_constant<is_bounded_array_v<_Tp>>
{ };
/// True for a type that is an array of unknown bound.
/// @since C++20
template<typename _Tp>
struct is_unbounded_array
: public bool_constant<is_unbounded_array_v<_Tp>>
{ };
#endif // __cpp_lib_bounded_array_traits
#if __has_builtin(__is_layout_compatible) && __cplusplus >= 202002L
/// @since C++20
template<typename _Tp, typename _Up>
struct is_layout_compatible
: bool_constant<__is_layout_compatible(_Tp, _Up)>
{ };
/// @ingroup variable_templates
/// @since C++20
template<typename _Tp, typename _Up>
constexpr bool is_layout_compatible_v
= __is_layout_compatible(_Tp, _Up);
#if __has_builtin(__builtin_is_corresponding_member)
# ifndef __cpp_lib_is_layout_compatible
# error "libstdc++ bug: is_corresponding_member and is_layout_compatible are provided but their FTM is not set"
# endif
/// @since C++20
template<typename _S1, typename _S2, typename _M1, typename _M2>
constexpr bool
is_corresponding_member(_M1 _S1::*__m1, _M2 _S2::*__m2) noexcept
{ return __builtin_is_corresponding_member(__m1, __m2); }
#endif
#endif
#if __has_builtin(__is_pointer_interconvertible_base_of) \
&& __cplusplus >= 202002L
/// True if `_Derived` is standard-layout and has a base class of type `_Base`
/// @since C++20
template<typename _Base, typename _Derived>
struct is_pointer_interconvertible_base_of
: bool_constant<__is_pointer_interconvertible_base_of(_Base, _Derived)>
{ };
/// @ingroup variable_templates
/// @since C++20
template<typename _Base, typename _Derived>
constexpr bool is_pointer_interconvertible_base_of_v
= __is_pointer_interconvertible_base_of(_Base, _Derived);
#if __has_builtin(__builtin_is_pointer_interconvertible_with_class)
# ifndef __cpp_lib_is_pointer_interconvertible
# error "libstdc++ bug: is_pointer_interconvertible available but FTM is not set"
# endif
/// True if `__mp` points to the first member of a standard-layout type
/// @returns true if `s.*__mp` is pointer-interconvertible with `s`
/// @since C++20
template<typename _Tp, typename _Mem>
constexpr bool
is_pointer_interconvertible_with_class(_Mem _Tp::*__mp) noexcept
{ return __builtin_is_pointer_interconvertible_with_class(__mp); }
#endif
#endif
#ifdef __cpp_lib_is_scoped_enum // C++ >= 23
/// True if the type is a scoped enumeration type.
/// @since C++23
# if _GLIBCXX_USE_BUILTIN_TRAIT(__is_scoped_enum)
template<typename _Tp>
struct is_scoped_enum
: bool_constant<__is_scoped_enum(_Tp)>
{ };
# else
template<typename _Tp>
struct is_scoped_enum
: false_type
{ };
template<typename _Tp>
requires __is_enum(_Tp)
&& requires(remove_cv_t<_Tp> __t) { __t = __t; } // fails if incomplete
struct is_scoped_enum<_Tp>
: bool_constant<!requires(_Tp __t, void(*__f)(int)) { __f(__t); }>
{ };
# endif
/// @ingroup variable_templates
/// @since C++23
# if _GLIBCXX_USE_BUILTIN_TRAIT(__is_scoped_enum)
template<typename _Tp>
inline constexpr bool is_scoped_enum_v = __is_scoped_enum(_Tp);
# else
template<typename _Tp>
inline constexpr bool is_scoped_enum_v = is_scoped_enum<_Tp>::value;
# endif
#endif
#ifdef __cpp_lib_is_implicit_lifetime // C++ >= 23
/// True if the type is an implicit-lifetime type.
/// @since C++23
template<typename _Tp>
struct is_implicit_lifetime
: bool_constant<__builtin_is_implicit_lifetime(_Tp)>
{ };
/// @ingroup variable_templates
/// @since C++23
template<typename _Tp>
inline constexpr bool is_implicit_lifetime_v
= __builtin_is_implicit_lifetime(_Tp);
#endif
#ifdef __cpp_lib_reference_from_temporary // C++ >= 23 && ref_{converts,constructs}_from_temp
/// True if _Tp is a reference type, a _Up value can be bound to _Tp in
/// direct-initialization, and a temporary object would be bound to
/// the reference, false otherwise.
/// @since C++23
template<typename _Tp, typename _Up>
struct reference_constructs_from_temporary
: public bool_constant<__reference_constructs_from_temporary(_Tp, _Up)>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{})
&& std::__is_complete_or_unbounded(__type_identity<_Up>{}),
"template argument must be a complete class or an unbounded array");
};
/// True if _Tp is a reference type, a _Up value can be bound to _Tp in
/// copy-initialization, and a temporary object would be bound to
/// the reference, false otherwise.
/// @since C++23
template<typename _Tp, typename _Up>
struct reference_converts_from_temporary
: public bool_constant<__reference_converts_from_temporary(_Tp, _Up)>
{
static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{})
&& std::__is_complete_or_unbounded(__type_identity<_Up>{}),
"template argument must be a complete class or an unbounded array");
};
/// @ingroup variable_templates
/// @since C++23
template<typename _Tp, typename _Up>
inline constexpr bool reference_constructs_from_temporary_v
= reference_constructs_from_temporary<_Tp, _Up>::value;
/// @ingroup variable_templates
/// @since C++23
template<typename _Tp, typename _Up>
inline constexpr bool reference_converts_from_temporary_v
= reference_converts_from_temporary<_Tp, _Up>::value;
#endif // __cpp_lib_reference_from_temporary
#ifdef __cpp_lib_is_constant_evaluated // C++ >= 20 && HAVE_IS_CONST_EVAL
/// Returns true only when called during constant evaluation.
/// @since C++20
[[__gnu__::__always_inline__]]
constexpr bool
is_constant_evaluated() noexcept
{
#if __cpp_if_consteval >= 202106L
if consteval { return true; } else { return false; }
#else
return __builtin_is_constant_evaluated();
#endif
}
#endif
#if __cplusplus >= 202002L
/// @cond undocumented
template<typename _From, typename _To>
using __copy_cv = typename __match_cv_qualifiers<_From, _To>::__type;
template<typename _Xp, typename _Yp>
using __cond_res
= decltype(false ? declval<_Xp(&)()>()() : declval<_Yp(&)()>()());
template<typename _Ap, typename _Bp, typename = void>
struct __common_ref_impl
{ };
// [meta.trans.other], COMMON-REF(A, B)
template<typename _Ap, typename _Bp>
using __common_ref = typename __common_ref_impl<_Ap, _Bp>::type;
// COND-RES(COPYCV(X, Y) &, COPYCV(Y, X) &)
template<typename _Xp, typename _Yp>
using __condres_cvref
= __cond_res<__copy_cv<_Xp, _Yp>&, __copy_cv<_Yp, _Xp>&>;
// If A and B are both lvalue reference types, ...
template<typename _Xp, typename _Yp>
struct __common_ref_impl<_Xp&, _Yp&, __void_t<__condres_cvref<_Xp, _Yp>>>
: enable_if<is_reference_v<__condres_cvref<_Xp, _Yp>>,
__condres_cvref<_Xp, _Yp>>
{ };
// let C be remove_reference_t<COMMON-REF(X&, Y&)>&&
template<typename _Xp, typename _Yp>
using __common_ref_C = remove_reference_t<__common_ref<_Xp&, _Yp&>>&&;
// If A and B are both rvalue reference types, ...
template<typename _Xp, typename _Yp>
struct __common_ref_impl<_Xp&&, _Yp&&,
_Require<is_convertible<_Xp&&, __common_ref_C<_Xp, _Yp>>,
is_convertible<_Yp&&, __common_ref_C<_Xp, _Yp>>>>
{ using type = __common_ref_C<_Xp, _Yp>; };
// let D be COMMON-REF(const X&, Y&)
template<typename _Xp, typename _Yp>
using __common_ref_D = __common_ref<const _Xp&, _Yp&>;
// If A is an rvalue reference and B is an lvalue reference, ...
template<typename _Xp, typename _Yp>
struct __common_ref_impl<_Xp&&, _Yp&,
_Require<is_convertible<_Xp&&, __common_ref_D<_Xp, _Yp>>>>
{ using type = __common_ref_D<_Xp, _Yp>; };
// If A is an lvalue reference and B is an rvalue reference, ...
template<typename _Xp, typename _Yp>
struct __common_ref_impl<_Xp&, _Yp&&>
: __common_ref_impl<_Yp&&, _Xp&>
{ };
/// @endcond
template<typename _Tp, typename _Up,
template<typename> class _TQual, template<typename> class _UQual>
struct basic_common_reference
{ };
/// @cond undocumented
template<typename _Tp>
struct __xref
{ template<typename _Up> using __type = __copy_cv<_Tp, _Up>; };
template<typename _Tp>
struct __xref<_Tp&>
{ template<typename _Up> using __type = __copy_cv<_Tp, _Up>&; };
template<typename _Tp>
struct __xref<_Tp&&>
{ template<typename _Up> using __type = __copy_cv<_Tp, _Up>&&; };
template<typename _Tp1, typename _Tp2>
using __basic_common_ref
= typename basic_common_reference<remove_cvref_t<_Tp1>,
remove_cvref_t<_Tp2>,
__xref<_Tp1>::template __type,
__xref<_Tp2>::template __type>::type;
/// @endcond
template<typename... _Tp>
struct common_reference;
template<typename... _Tp>
using common_reference_t = typename common_reference<_Tp...>::type;
// If sizeof...(T) is zero, there shall be no member type.
template<>
struct common_reference<>
{ };
// If sizeof...(T) is one ...
template<typename _Tp0>
struct common_reference<_Tp0>
{ using type = _Tp0; };
/// @cond undocumented
template<typename _Tp1, typename _Tp2, int _Bullet = 1>
struct __common_reference_impl
: __common_reference_impl<_Tp1, _Tp2, _Bullet + 1>
{ };
// If sizeof...(T) is two ...
template<typename _Tp1, typename _Tp2>
struct common_reference<_Tp1, _Tp2>
: __common_reference_impl<_Tp1, _Tp2>
{ };
// If T1 and T2 are reference types and COMMON-REF(T1, T2) is well-formed, ...
template<typename _Tp1, typename _Tp2>
requires is_reference_v<_Tp1> && is_reference_v<_Tp2>
&& requires { typename __common_ref<_Tp1, _Tp2>; }
#if __cpp_lib_common_reference // C++ >= 20
&& is_convertible_v<add_pointer_t<_Tp1>,
add_pointer_t<__common_ref<_Tp1, _Tp2>>>
&& is_convertible_v<add_pointer_t<_Tp2>,
add_pointer_t<__common_ref<_Tp1, _Tp2>>>
#endif
struct __common_reference_impl<_Tp1, _Tp2, 1>
{ using type = __common_ref<_Tp1, _Tp2>; };
// Otherwise, if basic_common_reference<...>::type is well-formed, ...
template<typename _Tp1, typename _Tp2>
requires requires { typename __basic_common_ref<_Tp1, _Tp2>; }
struct __common_reference_impl<_Tp1, _Tp2, 2>
{ using type = __basic_common_ref<_Tp1, _Tp2>; };
// Otherwise, if COND-RES(T1, T2) is well-formed, ...
template<typename _Tp1, typename _Tp2>
requires requires { typename __cond_res<_Tp1, _Tp2>; }
struct __common_reference_impl<_Tp1, _Tp2, 3>
{ using type = __cond_res<_Tp1, _Tp2>; };
// Otherwise, if common_type_t<T1, T2> is well-formed, ...
template<typename _Tp1, typename _Tp2>
requires requires { typename common_type_t<_Tp1, _Tp2>; }
struct __common_reference_impl<_Tp1, _Tp2, 4>
{ using type = common_type_t<_Tp1, _Tp2>; };
// Otherwise, there shall be no member type.
template<typename _Tp1, typename _Tp2>
struct __common_reference_impl<_Tp1, _Tp2, 5>
{ };
// Otherwise, if sizeof...(T) is greater than two, ...
template<typename _Tp1, typename _Tp2, typename... _Rest>
struct common_reference<_Tp1, _Tp2, _Rest...>
: __common_type_fold<common_reference<_Tp1, _Tp2>,
__common_type_pack<_Rest...>>
{ };
// Reuse __common_type_fold for common_reference<T1, T2, Rest...>
template<typename _Tp1, typename _Tp2, typename... _Rest>
struct __common_type_fold<common_reference<_Tp1, _Tp2>,
__common_type_pack<_Rest...>,
void_t<common_reference_t<_Tp1, _Tp2>>>
: public common_reference<common_reference_t<_Tp1, _Tp2>, _Rest...>
{ };
/// @endcond
#endif // C++20
#if __cplusplus >= 201103L
// 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 { };
// Builds an _Index_tuple<0, 1, 2, ..., _Num-1>.
template<size_t _Num>
struct _Build_index_tuple
{
#if __has_builtin(__make_integer_seq)
template<typename, size_t... _Indices>
using _IdxTuple = _Index_tuple<_Indices...>;
// Clang defines __make_integer_seq for this purpose.
using __type = __make_integer_seq<_IdxTuple, size_t, _Num>;
#else
// For GCC and other compilers, use __integer_pack instead.
using __type = _Index_tuple<__integer_pack(_Num)...>;
#endif
};
#endif // C++11
/// @} group metaprogramming
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
} // extern "C++"
#endif // C++11
#endif // _GLIBCXX_TYPE_TRAITS
c++0x_warning.h
version.h
c++config.h
std::aligned_union::alignment_value
static const size_t alignment_value
The value of the strictest alignment of _Types.
Definition type_traits:2480
std::is_corresponding_member
constexpr bool is_corresponding_member(_M1 _S1::*__m1, _M2 _S2::*__m2) noexcept
Definition type_traits:4062
std::common_reference_t
typename common_reference< _Tp... >::type common_reference_t
Definition type_traits:4289
std::result_of_t
typename result_of< _Tp >::type result_of_t
Alias template for result_of.
Definition type_traits:2960
std::aligned_union::type
typename aligned_storage< _S_len, alignment_value >::type type
The storage.
Definition type_traits:2482
std::true_type
__bool_constant< true > true_type
The type used as a compile-time boolean with true value.
Definition type_traits:119
std::remove_extent_t
typename remove_extent< _Tp >::type remove_extent_t
Alias template for remove_extent.
Definition type_traits:2296
std::conditional_t
typename conditional< _Cond, _Iftrue, _Iffalse >::type conditional_t
Alias template for conditional.
Definition type_traits:2948
std::underlying_type_t
typename underlying_type< _Tp >::type underlying_type_t
Alias template for underlying_type.
Definition type_traits:2956
std::make_signed_t
typename make_signed< _Tp >::type make_signed_t
Alias template for make_signed.
Definition type_traits:2246
std::add_lvalue_reference_t
typename add_lvalue_reference< _Tp >::type add_lvalue_reference_t
Alias template for add_lvalue_reference.
Definition type_traits:1894
std::aligned_storage_t
typename aligned_storage< _Len, _Align >::type aligned_storage_t
Alias template for aligned_storage.
Definition type_traits:2932
std::remove_reference_t
typename remove_reference< _Tp >::type remove_reference_t
Alias template for remove_reference.
Definition type_traits:1890
std::common_type_t
typename common_type< _Tp... >::type common_type_t
Alias template for common_type.
Definition type_traits:2952
std::add_pointer_t
typename add_pointer< _Tp >::type add_pointer_t
Alias template for add_pointer.
Definition type_traits:2360
std::make_unsigned_t
typename make_unsigned< _Tp >::type make_unsigned_t
Alias template for make_unsigned.
Definition type_traits:2250
std::is_pointer_interconvertible_with_class
constexpr bool is_pointer_interconvertible_with_class(_Mem _Tp::*__mp) noexcept
True if __mp points to the first member of a standard-layout type.
Definition type_traits:4092
std::enable_if_t
typename enable_if< _Cond, _Tp >::type enable_if_t
Alias template for enable_if.
Definition type_traits:2944
std::remove_all_extents_t
typename remove_all_extents< _Tp >::type remove_all_extents_t
Alias template for remove_all_extents.
Definition type_traits:2300
std::remove_pointer_t
typename remove_pointer< _Tp >::type remove_pointer_t
Alias template for remove_pointer.
Definition type_traits:2356
std::add_rvalue_reference_t
typename add_rvalue_reference< _Tp >::type add_rvalue_reference_t
Alias template for add_rvalue_reference.
Definition type_traits:1898
std::false_type
__bool_constant< false > false_type
The type used as a compile-time boolean with false value.
Definition type_traits:122
std::is_layout_compatible_v
constexpr bool is_layout_compatible_v
Definition type_traits:4052
std::is_pointer_interconvertible_base_of_v
constexpr bool is_pointer_interconvertible_base_of_v
Definition type_traits:4080
std::decay_t
typename decay< _Tp >::type decay_t
Alias template for decay.
Definition type_traits:2940
std::declval
auto declval() noexcept -> decltype(__declval< _Tp >(0))
Definition type_traits:2718
std::experimental::fundamentals_v2::void_t
void void_t
A metafunction that always yields void, used for detecting valid types.
Definition experimental/type_traits:262
std
ISO C++ entities toplevel namespace is std.
std::__detail
Implementation details not part of the namespace std interface.
std::reference_wrapper
Primary class template for reference_wrapper.
Definition refwrap.h:316
std::integral_constant
integral_constant
Definition type_traits:96
std::enable_if
Define a member typedef type only if a boolean constant is true.
Definition type_traits:137
std::is_object
is_object
Definition type_traits:857
std::remove_cv
remove_cv
Definition type_traits:1796
std::is_const
is_const
Definition type_traits:926
std::is_void
is_void
Definition type_traits:331
std::is_integral
is_integral
Definition type_traits:541
std::is_floating_point
is_floating_point
Definition type_traits:601
std::is_array
is_array
Definition type_traits:608
std::is_pointer
is_pointer
Definition type_traits:628
std::is_lvalue_reference
is_lvalue_reference
Definition type_traits:654
std::is_rvalue_reference
is_rvalue_reference
Definition type_traits:663
std::is_member_object_pointer
is_member_object_pointer
Definition type_traits:674
std::is_member_function_pointer
is_member_function_pointer
Definition type_traits:699
std::is_enum
is_enum
Definition type_traits:723
std::is_union
is_union
Definition type_traits:729
std::is_class
is_class
Definition type_traits:735
std::is_function
is_function
Definition type_traits:742
std::is_reference
is_reference
Definition type_traits:817
std::is_arithmetic
is_arithmetic
Definition type_traits:839
std::is_fundamental
is_fundamental
Definition type_traits:850
std::is_member_pointer
is_member_pointer
Definition type_traits:890
std::is_scalar
is_scalar
Definition type_traits:878
std::is_compound
is_compound
Definition type_traits:883
std::is_same
is_same
Definition type_traits:1626
std::is_volatile
is_volatile
Definition type_traits:942
std::is_trivial
Definition type_traits:965
std::is_trivially_copyable
is_trivially_copyable
Definition type_traits:974
std::is_standard_layout
is_standard_layout
Definition type_traits:983
std::is_pod
Definition type_traits:998
std::is_literal_type
Definition type_traits:1012
std::is_empty
is_empty
Definition type_traits:1021
std::is_polymorphic
is_polymorphic
Definition type_traits:1027
std::is_abstract
is_abstract
Definition type_traits:1042
std::is_signed
is_signed
Definition type_traits:1060
std::is_unsigned
is_unsigned
Definition type_traits:1066
std::remove_all_extents
remove_all_extents
Definition type_traits:2278
std::is_destructible
is_destructible
Definition type_traits:1113
std::is_nothrow_destructible
is_nothrow_destructible
Definition type_traits:1175
std::is_constructible
is_constructible
Definition type_traits:1242
std::is_default_constructible
is_default_constructible
Definition type_traits:1251
std::is_copy_constructible
is_copy_constructible
Definition type_traits:1278
std::is_move_constructible
is_move_constructible
Definition type_traits:1305
std::is_nothrow_constructible
is_nothrow_constructible
Definition type_traits:1320
std::is_nothrow_default_constructible
is_nothrow_default_constructible
Definition type_traits:1329
std::is_nothrow_copy_constructible
is_nothrow_copy_constructible
Definition type_traits:1338
std::is_nothrow_move_constructible
is_nothrow_move_constructible
Definition type_traits:1347
std::is_assignable
is_assignable
Definition type_traits:1361
std::is_copy_assignable
is_copy_assignable
Definition type_traits:1371
std::is_move_assignable
is_move_assignable
Definition type_traits:1380
std::is_nothrow_assignable
is_nothrow_assignable
Definition type_traits:1395
std::is_nothrow_copy_assignable
is_nothrow_copy_assignable
Definition type_traits:1405
std::is_nothrow_move_assignable
is_nothrow_move_assignable
Definition type_traits:1415
std::is_trivially_constructible
is_trivially_constructible
Definition type_traits:1430
std::is_trivially_default_constructible
is_trivially_default_constructible
Definition type_traits:1439
std::is_trivially_copy_constructible
is_trivially_copy_constructible
Definition type_traits:1489
std::is_trivially_move_constructible
is_trivially_move_constructible
Definition type_traits:1498
std::is_trivially_assignable
is_trivially_assignable
Definition type_traits:1513
std::is_trivially_copy_assignable
is_trivially_copy_assignable
Definition type_traits:1523
std::is_trivially_move_assignable
is_trivially_move_assignable
Definition type_traits:1533
std::is_trivially_destructible
is_trivially_destructible
Definition type_traits:1543
std::has_virtual_destructor
has_virtual_destructor
Definition type_traits:1560
std::alignment_of
alignment_of
Definition type_traits:1572
std::rank
rank
Definition type_traits:1582
std::extent
extent
Definition type_traits:1600
std::is_base_of
is_base_of
Definition type_traits:1643
std::remove_const
remove_const
Definition type_traits:1777
std::remove_volatile
remove_volatile
Definition type_traits:1786
std::add_const
add_const
Definition type_traits:1818
std::add_volatile
add_volatile
Definition type_traits:1823
std::add_cv
add_cv
Definition type_traits:1828
std::remove_reference
remove_reference
Definition type_traits:1862
std::add_lvalue_reference
add_lvalue_reference
Definition type_traits:1880
std::add_rvalue_reference
add_rvalue_reference
Definition type_traits:1885
std::make_unsigned
make_unsigned
Definition type_traits:2097
std::make_signed
make_signed
Definition type_traits:2235
std::remove_extent
remove_extent
Definition type_traits:2259
std::remove_pointer
remove_pointer
Definition type_traits:2309
std::add_pointer
add_pointer
Definition type_traits:2329
std::aligned_storage
Aligned storage.
Definition type_traits:2427
std::aligned_union
Provide aligned storage for types.
Definition type_traits:2471
std::conditional
Define a member typedef type to one of two argument types.
Definition type_traits:2568
std::common_type
common_type
Definition type_traits:2577
std::underlying_type
The underlying type of an enum.
Definition type_traits:2703
std::result_of
result_of
Definition type_traits:2727
std::is_layout_compatible
Definition type_traits:4046
std::is_pointer_interconvertible_base_of
True if _Derived is standard-layout and has a base class of type _Base.
Definition type_traits:4074