< cpp‎ | types
Type support
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(C++11)(deprecated in C++17)
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(C++11)(deprecated in C++17)(C++17)
Defined in header <type_traits>
template< class T >
struct add_pointer;
(since C++11)

If T is a reference type, then provides the member typedef type which is a pointer to the referred type.

Otherwise, if T names an object type, a function type that is not cv- or ref-qualified (since C++17), or a (possibly cv-qualified) void type, provides the member typedef type which is the type T*.

Otherwise (if T is a cv- or ref-qualified function type), provides the member typedef type which is the type T

(since C++17)


[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

namespace detail {
template< class T, bool is_function_type = false >
struct add_pointer {
    using type = typename std::remove_reference<T>::type*;
template< class T >
struct add_pointer<T, true> {
    using type = T;
template< class T, class... Args >
struct add_pointer<T(Args...), true> {
    using type = T(*)(Args...);
template< class T, class... Args >
struct add_pointer<T(Args..., ...), true> {
    using type = T(*)(Args..., ...);
} // namespace detail
template< class T >
struct add_pointer : detail::add_pointer<T, std::is_function<T>::value> {};

[edit] Example

#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, "IntAgain should be equal to int");


i = 123
*pi = 123
j = 123

[edit] See also

checks if a type is a pointer type
(class template) [edit]
removes pointer from the given type
(class template) [edit]