# std::experimental::static_pointer_cast, std::experimental::dynamic_pointer_cast, std::experimental::const_pointer_cast, std::experimental::reinterpret_pointer_cast

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< cpp‎ | experimental‎ | shared ptr

template< class T, class U > std::experimental::shared_ptr<T> static_pointer_cast( const std::experimental::shared_ptr<U>& r ); | (1) | (library fundamentals TS)
template< class T, class U > std::experimental::shared_ptr<T> dynamic_pointer_cast( const std::experimental::shared_ptr<U>& r ); | (2) | (library fundamentals TS)
template< class T, class U > std::experimental::shared_ptr<T> const_pointer_cast( const std::experimental::shared_ptr<U>& r ); | (3) | (library fundamentals TS)
template< class T, class U > std::experimental::shared_ptr<T> reinterpret_pointer_cast( const std::experimental::shared_ptr<U>& r ); | (4) | (library fundamentals TS)

Creates a new instance of std::experimental::shared_ptr whose stored pointer is obtained from `r`'s stored pointer using a cast expression. If `r` is empty, so is the new `shared_ptr` (but its stored pointer is not necessarily null).

Otherwise, the new `shared_ptr` will share ownership with `r`, except that it is empty if the `dynamic_cast` performed by `dynamic_pointer_cast` returns a null pointer.

Let `Y` be typename std::experimental::shared_ptr<T>::element_type, then the resulting std::experimental::shared_ptr's stored pointer will be obtained by calling (in respective order):

1) static_cast<Y*>(r.get()).
2) dynamic_cast<Y*>(r.get()) (If the result of the `dynamic_cast` is a null pointer value, the returned `shared_ptr` will be empty).
3) const_cast<Y*>(r.get()).
4) reinterpret_cast<Y*>(r.get()).

The behavior of these functions is undefined unless the corresponding cast from `U*` to `T*` is well formed:

1) The behavior is undefined unless static_cast<T*>((U*)nullptr) is well formed.
2) The behavior is undefined unless dynamic_cast<T*>((U*)nullptr) is well formed.
3) The behavior is undefined unless const_cast<T*>((U*)nullptr) is well formed.
4) The behavior is undefined unless reinterpret_cast<T*>((U*)nullptr) is well formed.

### Parameters

r | - | The pointer to convert

### Exceptions

`noexcept` specification:
noexcept

### Example

| This section is incomplete Reason: no example

### See also

(constructor) | constructs new `shared_ptr` (public member function)
static_pointer_cast dynamic_pointer_cast const_pointer_cast reinterpret_pointer_cast (C++17) | applies `static_cast`, `dynamic_cast`, `const_cast`, or `reinterpret_cast` to the stored pointer (function template)

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