std::pointer_traits
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                    |   Defined in header <memory>
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|   template< class Ptr > struct pointer_traits;  | 
(1) | (since C++11) | 
|   template< class T > struct pointer_traits<T*>;  | 
(2) | (since C++11) | 
The pointer_traits class template provides the standardized way to access certain properties of pointer-like types.
1) The non-specialized pointer_traits declares the following types:
Contents | 
[edit] Member types
| Type | Definition | 
| pointer | Ptr | 
| element_type | Ptr::element_type if present. Otherwise T if Ptr is a template instantiation Template<T, Args...> | 
| difference_type | Ptr::difference_type if present, otherwise std::ptrdiff_t | 
[edit] Member alias templates
| Template | Definition | 
| template <class U> using rebind | Ptr::rebind<U> if exists, otherwise Tempate<U, Args...> if Ptr is a template instantiation Template<T, Args...> | 
[edit] Member functions
|    [static]  | 
   obtains a dereferencable pointer to its argument    (public static member function)  | 
2) A specialization is provided for pointer types, T*, which declares the following types
[edit] Member types
| Type | Definition | 
| pointer | T* | 
| element_type | T | 
| difference_type | std::ptrdiff_t | 
[edit] Member alias templates
| Template | Definition | 
| template< class U > using rebind | U* | 
[edit] Member functions
|    [static]  | 
   obtains a dereferencable pointer to its argument}   (public static member function)  | 
[edit] See also
|    (C++11)  | 
   provides information about allocator types   (class template)  | 
|    (C++11)  | 
   obtains actual address of an object, even if the & operator is overloaded   (function template)  |