std::experimental::observer_ptr::observer_ptr(3)

NAME
std::experimental::observer_ptr::observer_ptr - std::experimental::observer_ptr::observer_ptr

Synopsis
   constexpr observer_ptr() noexcept; (1) (library fundamentals TS v2)
   constexpr observer_ptr( nullptr_t ) noexcept;
   constexpr explicit observer_ptr( element_type* p ) (2) (library fundamentals TS v2)
   noexcept;
   template< class W2 >
   constexpr observer_ptr( observer_ptr<W2> other ) (3) (library fundamentals TS v2)
   noexcept;
   observer_ptr( const observer_ptr& other ) = (4) (library fundamentals TS v2)
   default; (implicitly declared)
   observer_ptr( observer_ptr&& other ) = default; (5) (library fundamentals TS v2)
                        (implicitly declared)
   1) Constructs an observer_ptr that has no corresponding watched object.
   2) Constructs an observer_ptr that watches p.
   3) Constructs an observer_ptr that watches other.get(). This overload participates
   in overload resolution only if W2* is convertible to element_type*.
   4,5) Implicitly declared copy and move constructors. Constructs an observer_ptr that
   watches other.get().

Parameters
   p - a pointer to an object to watch
   other - another observer_ptr to copy from