From cppreference.com
template<classT>structis_unbounded_array;(since C++20)std::is_unbounded_array is a
.
Checks whether T is an
. Provides the member constant value which is equal to true, if T is an array type of unknown bound. Otherwise, value is equal to false.
If the program adds specializations for std::is_unbounded_array or std::is_unbounded_array_v, the behavior is undefined.
Template parameters
T - a type to check Helper variable template
template<classT>constexprboolis_unbounded_array_v=is_unbounded_array<T>::value;(since C++20)Inherited from
Member constants
value
[static]
true if T is an array type of unknown bound., false otherwise
(public static member constant)Member functions
operator bool
converts the object to bool, returns value
(public member function)operator()
(C++14)
returns value
(public member function)Member types
Type Definition value_typebooltypestd::integral_constant<bool,value>Possible implementation
template<classT>structis_unbounded_array:std::false_type{};template<classT>structis_unbounded_array<T[]>:std::true_type{};Notes
macroValueStdFeature
__cpp_lib_bounded_array_traits
(C++20)
, std::is_unbounded_arrayExample
Run this code
#include<type_traits>classA{};static_assert(""&&std::is_unbounded_array_v<A>==false&&std::is_unbounded_array_v<A[]>==true&&std::is_unbounded_array_v<A[3]>==false&&std::is_unbounded_array_v<float>==false&&std::is_unbounded_array_v<int>==false&&std::is_unbounded_array_v<int[]>==true&&std::is_unbounded_array_v<int[3]>==false);intmain(){}See also