std::remove_extent

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Defined in header <type_traits>

template< class T >
struct remove_extent;
(C++11 feature)

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.

Contents

[edit] Member types

Name Definition
type the type of the element of T

[edit] Equivalent definition

[edit] Example

#include <iostream>
#include <iterator>
#include <algorithm>
#include <type_traits>
 
template<typename 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

[edit] See also

is_array (C++11)
checks if a type is an array type
(class template)
rank (C++11)
obtains the number of dimensions of an array type
(class template)
extent (C++11)
obtains the size of an array type along a specified dimension
(class template)
remove_all_extents (C++11)
removes all extents from the given array type
(class template)