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std::remove_pointer

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< cpp‎ | types
Revision as of 13:08, 23 August 2013 by Ruslo (Talk | contribs)

 
 
Utilities library
General utilities
Relational operators (deprecated in C++20)
 
 
Defined in header <type_traits>
template< class T >
struct remove_pointer;
(since C++11)

Provides the member typedef type which is the type pointed to by T, or, if T is not a pointer, then type is the same as T.

Contents

Member types

Name Definition
type the type pointed to by T or T if it's not a pointer

Helper types

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

Possible implementation

template< class T > struct remove_pointer                    {typedef T type;};
template< class T > struct remove_pointer<T*>                {typedef T type;};
template< class T > struct remove_pointer<T* const>          {typedef T type;};
template< class T > struct remove_pointer<T* volatile>       {typedef T type;};
template< class T > struct remove_pointer<T* const volatile> {typedef T type;};

Example

#include <iostream> // std::cout
#include <type_traits> // std::is_same
 
template<class T1, class T2>
void print_is_same() {
  std::cout << std::is_same<T1, T2>() << '\n';
}
 
int main() {
  std::cout << std::boolalpha;
 
  print_is_same<int, int>();   // true
  print_is_same<int, int*>();  // false
  print_is_same<int, int**>(); // false
 
  print_is_same<int, std::remove_pointer<int>::type>();   // true
  print_is_same<int, std::remove_pointer<int*>::type>();  // true
  print_is_same<int, std::remove_pointer<int**>::type>(); // false
 
  print_is_same<int, std::remove_pointer<int* const>::type>();          // true
  print_is_same<int, std::remove_pointer<int* volatile>::type>();       // true
  print_is_same<int, std::remove_pointer<int* const volatile>::type>(); // true
}

Output:

true
false
false
true
true
false
true
true
true

See also

checks if a type is a pointer type
(class template) [edit]
adds a pointer to the given type
(class template) [edit]