Std::remove_extent (3) Linux Manual Page

std::remove_extent – std::remove_extent

Synopsis

Defined in header<type_traits>

    template <class T>
    (since C++ 11)

        struct remove_extent;

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.

Member types

Name Definition
type the type of the element of T

Helper types

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

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; };

Example

// Run this code

#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
    print_1d(a[1]);
}

Output:

4 5 6

std::remove_extent (3) Linux Manual Page