std:: remove_cvref

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remove_cvref
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Defined in header <type_traits>
template < class T >
struct remove_cvref ;
(since C++20)

If the type T is a reference type, provides the member typedef type which is the type referred to by T with its topmost cv-qualifiers removed. Otherwise type is T with its topmost cv-qualifiers removed.

If the program adds specializations for std::remove_cvref , the behavior is undefined.

Member types

Name Definition
type the type referred by T or T itself if it is not a reference, with top-level cv-qualifiers removed

Helper types

template < class T >
using remove_cvref_t = remove_cvref < T > :: type ;
(since C++20)

Possible implementation 

template<class T>
struct remove_cvref
{
    using type = std::remove_cv_t<std::remove_reference_t<T>>;
};

Notes

Feature-test macro Value Std Feature
__cpp_lib_remove_cvref 201711L (C++20) std::remove_cvref

Example

Run this code 
#include <type_traits>
 
int main()
{
    static_assert(std::is_same_v<std::remove_cvref_t<int>, int>);
    static_assert(std::is_same_v<std::remove_cvref_t<int&>, int>);
    static_assert(std::is_same_v<std::remove_cvref_t<int&&>, int>);
    static_assert(std::is_same_v<std::remove_cvref_t<const int&>, int>);
    static_assert(std::is_same_v<std::remove_cvref_t<const int[2]>, int[2]>);
    static_assert(std::is_same_v<std::remove_cvref_t<const int(&)[2]>, int[2]>);
    static_assert(std::is_same_v<std::remove_cvref_t<int(int)>, int(int)>);
}

See also

(C++11) (C++11) (C++11)
removes const and/or volatile specifiers from the given type
(class template)
(C++11)
removes a reference from the given type
(class template)
(C++11)
applies type transformations as when passing a function argument by value
(class template)
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