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std::remove_extent(3)	      C++ Standard Libary	 std::remove_extent(3)

NAME
       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.

	  The  behavior	 of a program that adds	specializations	for remove_ex-
       tent is undefined.

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

http://cppreference.com		  2022.07.31		 std::remove_extent(3)

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