libstdc++
Variables
Variable templates for type traits
Collaboration diagram for Variable templates for type traits:

Variables

template<typename _Tp >
constexpr bool std::has_unique_object_representations_v
 
template<typename _Tp >
constexpr bool std::is_aggregate_v
 
template<typename _Tp >
constexpr bool std::is_bounded_array_v
 
template<typename _Tp , typename _Up >
constexpr bool std::is_layout_compatible_v
 
template<typename _Base , typename _Derived >
constexpr bool std::is_pointer_interconvertible_base_of_v
 
template<typename _Tp >
constexpr bool std::is_unbounded_array_v
 
template<typename... _Bn>
constexpr bool std::conjunction_v
 
template<typename... _Bn>
constexpr bool std::disjunction_v
 
template<typename _Pp >
constexpr bool std::negation_v
 
template<typename _Tp >
constexpr bool std::is_void_v
 
template<typename _Tp >
constexpr bool std::is_null_pointer_v
 
template<typename _Tp >
constexpr bool std::is_integral_v
 
template<typename _Tp >
constexpr bool std::is_floating_point_v
 
template<typename _Tp >
constexpr bool std::is_array_v
 
template<typename _Tp >
constexpr bool std::is_array_v< _Tp[]>
 
template<typename _Tp , size_t _Num>
constexpr bool std::is_array_v< _Tp[_Num]>
 
template<typename _Tp >
constexpr bool std::is_pointer_v
 
template<typename _Tp >
constexpr bool std::is_lvalue_reference_v
 
template<typename _Tp >
constexpr bool std::is_lvalue_reference_v< _Tp &>
 
template<typename _Tp >
constexpr bool std::is_rvalue_reference_v
 
template<typename _Tp >
constexpr bool std::is_rvalue_reference_v< _Tp &&>
 
template<typename _Tp >
constexpr bool std::is_member_object_pointer_v
 
template<typename _Tp >
constexpr bool std::is_member_function_pointer_v
 
template<typename _Tp >
constexpr bool std::is_enum_v
 
template<typename _Tp >
constexpr bool std::is_union_v
 
template<typename _Tp >
constexpr bool std::is_class_v
 
template<typename _Tp >
constexpr bool std::is_function_v
 
template<typename _Tp >
constexpr bool std::is_reference_v
 
template<typename _Tp >
constexpr bool std::is_reference_v< _Tp &>
 
template<typename _Tp >
constexpr bool std::is_reference_v< _Tp &&>
 
template<typename _Tp >
constexpr bool std::is_arithmetic_v
 
template<typename _Tp >
constexpr bool std::is_fundamental_v
 
template<typename _Tp >
constexpr bool std::is_object_v
 
template<typename _Tp >
constexpr bool std::is_scalar_v
 
template<typename _Tp >
constexpr bool std::is_compound_v
 
template<typename _Tp >
constexpr bool std::is_member_pointer_v
 
template<typename _Tp >
constexpr bool std::is_const_v
 
template<typename _Tp >
constexpr bool std::is_const_v< const _Tp >
 
template<typename _Tp >
constexpr bool std::is_volatile_v
 
template<typename _Tp >
constexpr bool std::is_volatile_v< volatile _Tp >
 
template<typename _Tp >
constexpr bool std::is_trivial_v
 
template<typename _Tp >
constexpr bool std::is_trivially_copyable_v
 
template<typename _Tp >
constexpr bool std::is_standard_layout_v
 
template<typename _Tp >
constexpr bool std::is_pod_v
 
template<typename _Tp >
constexpr bool std::is_literal_type_v
 
template<typename _Tp >
constexpr bool std::is_empty_v
 
template<typename _Tp >
constexpr bool std::is_polymorphic_v
 
template<typename _Tp >
constexpr bool std::is_abstract_v
 
template<typename _Tp >
constexpr bool std::is_final_v
 
template<typename _Tp >
constexpr bool std::is_signed_v
 
template<typename _Tp >
constexpr bool std::is_unsigned_v
 
template<typename _Tp , typename... _Args>
constexpr bool std::is_constructible_v
 
template<typename _Tp >
constexpr bool std::is_default_constructible_v
 
template<typename _Tp >
constexpr bool std::is_copy_constructible_v
 
template<typename _Tp >
constexpr bool std::is_move_constructible_v
 
template<typename _Tp , typename _Up >
constexpr bool std::is_assignable_v
 
template<typename _Tp >
constexpr bool std::is_copy_assignable_v
 
template<typename _Tp >
constexpr bool std::is_move_assignable_v
 
template<typename _Tp >
constexpr bool std::is_destructible_v
 
template<typename _Tp , typename... _Args>
constexpr bool std::is_trivially_constructible_v
 
template<typename _Tp >
constexpr bool std::is_trivially_default_constructible_v
 
template<typename _Tp >
constexpr bool std::is_trivially_copy_constructible_v
 
template<typename _Tp >
constexpr bool std::is_trivially_move_constructible_v
 
template<typename _Tp , typename _Up >
constexpr bool std::is_trivially_assignable_v
 
template<typename _Tp >
constexpr bool std::is_trivially_copy_assignable_v
 
template<typename _Tp >
constexpr bool std::is_trivially_move_assignable_v
 
template<typename _Tp >
constexpr bool std::is_trivially_destructible_v
 
template<typename _Tp , typename... _Args>
constexpr bool std::is_nothrow_constructible_v
 
template<typename _Tp >
constexpr bool std::is_nothrow_default_constructible_v
 
template<typename _Tp >
constexpr bool std::is_nothrow_copy_constructible_v
 
template<typename _Tp >
constexpr bool std::is_nothrow_move_constructible_v
 
template<typename _Tp , typename _Up >
constexpr bool std::is_nothrow_assignable_v
 
template<typename _Tp >
constexpr bool std::is_nothrow_copy_assignable_v
 
template<typename _Tp >
constexpr bool std::is_nothrow_move_assignable_v
 
template<typename _Tp >
constexpr bool std::is_nothrow_destructible_v
 
template<typename _Tp >
constexpr bool std::has_virtual_destructor_v
 
template<typename _Tp >
constexpr size_t std::alignment_of_v
 
template<typename _Tp >
constexpr size_t std::rank_v
 
template<typename _Tp , size_t _Size>
constexpr size_t std::rank_v< _Tp[_Size]>
 
template<typename _Tp >
constexpr size_t std::rank_v< _Tp[]>
 
template<typename _Tp , unsigned _Idx = 0>
constexpr size_t std::extent_v
 
template<typename _Tp , size_t _Size>
constexpr size_t std::extent_v< _Tp[_Size], 0 >
 
template<typename _Tp , unsigned _Idx, size_t _Size>
constexpr size_t std::extent_v< _Tp[_Size], _Idx >
 
template<typename _Tp >
constexpr size_t std::extent_v< _Tp[], 0 >
 
template<typename _Tp , unsigned _Idx>
constexpr size_t std::extent_v< _Tp[], _Idx >
 
template<typename _Tp , typename _Up >
constexpr bool std::is_same_v
 
template<typename _Tp >
constexpr bool std::is_same_v< _Tp, _Tp >
 
template<typename _Base , typename _Derived >
constexpr bool std::is_base_of_v
 
template<typename _From , typename _To >
constexpr bool std::is_convertible_v
 
template<typename _Fn , typename... _Args>
constexpr bool std::is_invocable_v
 
template<typename _Fn , typename... _Args>
constexpr bool std::is_nothrow_invocable_v
 
template<typename _Ret , typename _Fn , typename... _Args>
constexpr bool std::is_invocable_r_v
 
template<typename _Ret , typename _Fn , typename... _Args>
constexpr bool std::is_nothrow_invocable_r_v
 

Detailed Description

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.

Variable Documentation

◆ is_aggregate_v

template<typename _Tp >
constexpr bool std::is_aggregate_v
inline

is_aggregate_v - true if the type is an aggregate.

Since
C++17

Definition at line 3416 of file type_traits.

◆ is_bounded_array_v

template<typename _Tp >
constexpr bool std::is_bounded_array_v
inline

True for a type that is an array of known bound.

Since
C++20

Definition at line 3495 of file type_traits.

◆ is_layout_compatible_v

template<typename _Tp , typename _Up >
constexpr bool std::is_layout_compatible_v
Since
C++20

Definition at line 3535 of file type_traits.

◆ is_pointer_interconvertible_base_of_v

template<typename _Base , typename _Derived >
constexpr bool std::is_pointer_interconvertible_base_of_v
Since
C++20

Definition at line 3560 of file type_traits.

◆ is_unbounded_array_v

template<typename _Tp >
constexpr bool std::is_unbounded_array_v
inline

True for a type that is an array of unknown bound.

Since
C++20

Definition at line 3504 of file type_traits.