NAME

       std::weak_ptr< _Tp > - A non-owning observer for a pointer owned by a shared_ptr.

SYNOPSIS

       Inherits std::__weak_ptr< _Tp, _Lp >.

   Public Types
       using element_type = typename remove_extent< _Tp >::type

   Public Member Functions
       template<typename _Yp , typename  = _Constructible<const shared_ptr<_Yp>&>> weak_ptr
           (const shared_ptr< _Yp > &__r) noexcept
       weak_ptr (const weak_ptr &) noexcept=default
       template<typename _Yp , typename  = _Constructible<const weak_ptr<_Yp>&>> weak_ptr (const
           weak_ptr< _Yp > &__r) noexcept
       weak_ptr (weak_ptr &&) noexcept=default
       template<typename _Yp , typename  = _Constructible<weak_ptr<_Yp>>> weak_ptr (weak_ptr< _Yp
           > &&__r) noexcept
       bool expired () const noexcept
       shared_ptr< _Tp > lock () const noexcept
       template<typename _Yp > _Assignable< const shared_ptr< _Yp > & > operator= (const
           shared_ptr< _Yp > &__r) noexcept
       weak_ptr & operator= (const weak_ptr &__r) noexcept=default
       template<typename _Yp > _Assignable< const weak_ptr< _Yp > & > operator= (const weak_ptr<
           _Yp > &__r) noexcept
       weak_ptr & operator= (weak_ptr &&__r) noexcept=default
       template<typename _Yp > _Assignable< weak_ptr< _Yp > > operator= (weak_ptr< _Yp > &&__r)
           noexcept
       template<typename _Tp1 > bool owner_before (const __shared_ptr< _Tp1, _Lp > &__rhs) const
           noexcept
       template<typename _Tp1 > bool owner_before (const __weak_ptr< _Tp1, _Lp > &__rhs) const
           noexcept
       void reset () noexcept
       void swap (__weak_ptr &__s) noexcept
       long use_count () const noexcept

   Related Functions
       (Note that these are not member functions.)
       template<typename _Tp > void swap (weak_ptr< _Tp > &__a, weak_ptr< _Tp > &__b) noexcept
           Swap overload for weak_ptr.

Detailed Description

   template<typename _Tp>
       class std::weak_ptr< _Tp >" A non-owning observer for a pointer owned by a shared_ptr.

       A weak_ptr provides a safe alternative to a raw pointer when you want a non-owning
       reference to an object that is managed by a shared_ptr.

       Unlike a raw pointer, a weak_ptr can be converted to a new shared_ptr that shares
       ownership with every other shared_ptr that already owns the pointer. In other words you
       can upgrade from a non-owning 'weak' reference to an owning shared_ptr, without having
       access to any of the existing shared_ptr objects.

       Also unlike a raw pointer, a weak_ptr does not become 'dangling' after the object it
       points to has been destroyed. Instead, a weak_ptr becomes expired and can no longer be
       converted to a shared_ptr that owns the freed pointer, so you cannot accidentally access
       the pointed-to object after it has been destroyed.

       Definition at line 685 of file bits/shared_ptr.h.

Author

       Generated automatically by Doxygen for libstdc++ from the source code.