template<class T, class U> shared_ptr<T> static_pointer_cast(const shared_ptr<U>& r) noexcept;
Requires: The expression static_cast<T*>(r.get()) shall be well formed.
Returns: If r is empty, an empty shared_ptr<T>; otherwise, a shared_ptr<T> object that stores static_cast<T*>(r.get()) and shares ownership with r.
Postconditions: w.get() == static_cast<T*>(r.get()) and w.use_count() == r.use_count(), where w is the return value.
[ Note: The seemingly equivalent expression shared_ptr<T>(static_cast<T*>(r.get())) will eventually result in undefined behavior, attempting to delete the same object twice. — end note ]
template<class T, class U> shared_ptr<T> dynamic_pointer_cast(const shared_ptr<U>& r) noexcept;
Requires: The expression dynamic_cast<T*>(r.get()) shall be well formed and shall have well defined behavior.
Postcondition: w.get() == dynamic_cast<T*>(r.get()), where w is the return value.
[ Note: The seemingly equivalent expression shared_ptr<T>(dynamic_cast<T*>(r.get())) will eventually result in undefined behavior, attempting to delete the same object twice. — end note ]
template<class T, class U> shared_ptr<T> const_pointer_cast(const shared_ptr<U>& r) noexcept;
Requires: The expression const_cast<T*>(r.get()) shall be well formed.
Returns: If r is empty, an empty shared_ptr<T>; otherwise, a shared_ptr<T> object that stores const_cast<T*>(r.get()) and shares ownership with r.
Postconditions: w.get() == const_cast<T*>(r.get()) and w.use_count() == r.use_count(), where w is the return value.
[ Note: The seemingly equivalent expression shared_ptr<T>(const_cast<T*>(r.get())) will eventually result in undefined behavior, attempting to delete the same object twice. — end note ]