std::add_pointer
From cppreference.com
Defined in header
<type_traits>
|
||
template< class T >
struct add_pointer; |
(since C++11) | |
Provides the member typedef type
which is the type T*
. If T
is a reference type, then type
is a pointer to the referred type.
Contents |
[edit] Member types
Name | Definition |
type
|
pointer to T or to the type referenced by T
|
[edit] Helper types
template< class T >
using add_pointer_t = typename add_pointer<T>::type; |
(since C++14) | |
[edit] Possible implementation
template< class T > struct add_pointer { typedef typename std::remove_reference<T>::type* type; }; |
[edit] Example
Run this code
#include <iostream> #include <type_traits> int main() { int i = 123; int& ri = i; typedef std::add_pointer<decltype(i)>::type IntPtr; typedef std::add_pointer<decltype(ri)>::type IntPtr2; IntPtr pi = &i; std::cout << "i = " << i << "\n"; std::cout << "*pi = " << *pi << "\n"; static_assert(std::is_pointer<IntPtr>::value, "IntPtr should be a pointer"); static_assert(std::is_same<IntPtr, int*>::value, "IntPtr should be a pointer to int"); static_assert(std::is_same<IntPtr2, IntPtr>::value, "IntPtr2 should be equal to IntPtr"); typedef std::remove_pointer<IntPtr>::type IntAgain; IntAgain j = i; std::cout << "j = " << j << "\n"; static_assert(!std::is_pointer<IntAgain>::value, "IntAgain should not be a pointer"); static_assert(std::is_same<IntAgain, int>::value, "IntPtr should be equal to int"); }
Output:
i = 123 *pi = 123 j = 123
[edit] See also
(C++11)
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checks if a type is a pointer type (class template) |
(C++11)
|
removes pointer from the given type (class template) |