Defined in header <type_traits>
template< class T >
struct remove_extent;
(since C++11)

If T is an array of some type X, provides the member typedef type equal to X, otherwise type is T. Note that if T is a multidimensional array, only the first dimension is removed.

The behavior of a program that adds specializations for remove_extent is undefined.

Member types

Name Definition
type the type of the element of T

Helper types

template< class T >
using remove_extent_t = typename remove_extent<T>::type;
(since C++14)

Possible implementation

template<class T>
struct remove_extent { typedef T type; };
template<class T>
struct remove_extent<T[]> { typedef T type; };
template<class T, std::size_t N>
struct remove_extent<T[N]> { typedef T type; };


#include <iostream>
#include <iterator>
#include <algorithm>
#include <type_traits>
template<class A>
typename std::enable_if< std::rank<A>::value == 1 >::type
print_1d(const A& a)
    copy(a, a+std::extent<A>::value,
         std::ostream_iterator<typename std::remove_extent<A>::type>(std::cout, " "));
    std::cout << '\n';
int main()
    int a[][3] = {{1,2,3},{4,5,6}};
//  print_1d(a); // compile-time error


4 5 6

See also

checks if a type is an array type
(class template)
obtains the number of dimensions of an array type
(class template)
obtains the size of an array type along a specified dimension
(class template)
removes all extents from the given array type
(class template)

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