# std::pointer_traits<Ptr>::pointer_to

From cppreference.com
< cpp‎ | memory‎ | pointer traits

Defined in header `<memory>` |  |
static pointer pointer_to( element_type& r ); | (1) | (since C++11) (member of `pointer_traits<Ptr>` specialization)
| (2) |
static pointer pointer_to( element_type& r ) noexcept; |  | (since C++11) (until C++20) (member of `pointer_traits<T*>` specialization)
static constexpr pointer pointer_to( element_type& r ) noexcept; |  | (since C++20) (member of `pointer_traits<T*>` specialization)

Constructs a dereferenceable pointer or pointer-like object ("fancy pointer") to its argument.

1) The version of this function in the non-specialized std::pointer_traits template simply calls Ptr::pointer_to(r), and if Ptr does not provide a static member function `pointer_to`, instantiation of this function is a compile-time error.
2) The version of this function in the specialization of std::pointer_traits for pointer types returns std::addressof(r).

### Parameters

r | - | reference to an object of type element_type&, except if element_type is void, in which case the type of `r` is unspecified

### Return value

A dereferenceable pointer to r, of the type pointer_traits<>::pointer.

### Exceptions

1) Unspecified (typically same as Ptr::pointer_to).

### Notes

The Boost.Intrusive library version of this function returns pointer(std::addressof(r)) if Ptr::pointer_to does not exist.

### See also

addressof (C++11) | obtains actual address of an object, even if the & operator is overloaded (function template)
address (until C++20) | obtains the address of an object, even if operator& is overloaded (public member function of `std::allocator<T>`)
to_address [static] (C++20)(optional) | obtains a raw pointer from a fancy pointer (inverse of `pointer_to`) (public static member function)
to_address (C++20) | obtains a raw pointer from a pointer-like type (function template)

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/memory/pointer_traits/pointer_to&oldid=153371"