is_pointer

| Home | Libraries | People | FAQ | More

### is_pointer

    template <class T>
    struct is_pointer : public true_type-or-false_type {};

Inherits: If T is a (possibly cv-qualified) pointer type (includes function pointers, but excludes pointers to members) then inherits from true_type, otherwise inherits from false_type.

C++ Standard Reference: 3.9.2p2 and 8.3.1.

Header: `#include <boost/type_traits/is_pointer.hpp>` or `#include <boost/type_traits.hpp>`

Examples:

> `is_pointer<int*>` inherits from `true_type`.

> `is_pointer<char* const>::type` is the type `true_type`.

> `is_pointer<int (*)(long)>::value` is an integral constant expression that evaluates to true.

> `is_pointer<int (MyClass::*)(long)>::value` is an integral constant expression that evaluates to false.

> `is_pointer<int (MyClass::*)>::value` is an integral constant expression that evaluates to false.

> `is_pointer<T>::value_type` is the type `bool`.

| Important
`is_pointer` detects "real" pointer types only, and not smart pointers. Users should not specialise `is_pointer` for smart pointer types, as doing so may cause Boost (and other third party) code to fail to function correctly. Users wanting a trait to detect smart pointers should create their own. However, note that there is no way in general to auto-magically detect smart pointer types, so such a trait would have to be partially specialised for each supported smart pointer type.