Defined in header <type_traits> | ||
|---|---|---|
template< class T > struct remove_all_extents; | (since C++11) |
If T is a multidimensional array of some type X, provides the member typedef type equal to X, otherwise type is T.
The behavior of a program that adds specializations for remove_all_extents is undefined.
| Name | Definition |
|---|---|
type | the type of the element of T |
template< class T > using remove_all_extents_t = typename remove_all_extents<T>::type; | (since C++14) |
template<class T>
struct remove_all_extents { typedef T type; };
template<class T>
struct remove_all_extents<T[]> {
typedef typename remove_all_extents<T>::type type;
};
template<class T, std::size_t N>
struct remove_all_extents<T[N]> {
typedef typename remove_all_extents<T>::type type;
}; |
#include <iostream>
#include <type_traits>
#include <typeinfo>
template<class A>
void info(const A&)
{
typedef typename std::remove_all_extents<A>::type Type;
std::cout << "underlying type: " << typeid(Type).name() << '\n';
}
int main()
{
float a0;
float a1[1][2][3];
float a2[1][1][1][1][2];
float* a3;
int a4[3][2];
double a5[2][3];
struct X { int m; } x0[3][3];
info(a0);
info(a1);
info(a2);
info(a3);
info(a4);
info(a5);
info(x0);
}Possible output:
underlying type: float underlying type: float underlying type: float underlying type: float* underlying type: int underlying type: double underlying type: main::X
|
(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 one extent from the given array type (class template) |
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