std::remove_extent
From cppreference.com
| Defined in header <type_traits>
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| 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.
Member types
| Name | Definition |
type
|
the type of the element of T
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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; }; |
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
See also
| (C++11) |
checks if a type is an array type (class template) |
| (C++11) |
obtains the number of dimensions of an array type (class template) |
| (C++11) |
obtains the size of an array type along a specified dimension (class template) |
| (C++11) |
removes all extents from the given array type (class template) |