std::remove_pointer (3) - Linux Manuals

std::remove_pointer: std::remove_pointer

NAME

std::remove_pointer - std::remove_pointer

Synopsis

Defined in header <type_traits>
template< class T > (since C++11)
struct remove_pointer;

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.

Member types

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

Helper types

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

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

// Run this code

  #include <iostream>
  #include <type_traits>

  template<class T1, class T2>
  void print_is_same()
  {
      std::cout << std::is_same<T1, T2>() << '\n';
  }

  void print_separator()
  {
      std::cout << "-----\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_separator();

      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_separator();

      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