23 General utilities library [utilities]

23.11 Smart pointers [smartptr]

23.11.4 Class template weak_­ptr [util.smartptr.weak]

23.11.4.3 weak_­ptr assignment [util.smartptr.weak.assign]

weak_ptr& operator=(const weak_ptr& r) noexcept; template<class Y> weak_ptr& operator=(const weak_ptr<Y>& r) noexcept; template<class Y> weak_ptr& operator=(const shared_ptr<Y>& r) noexcept;
Effects: Equivalent to weak_­ptr(r).swap(*this).
Remarks: The implementation may meet the effects (and the implied guarantees) via different means, without creating a temporary object.
Returns: *this.
weak_ptr& operator=(weak_ptr&& r) noexcept; template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept;
Effects: Equivalent to weak_­ptr(std​::​move(r)).swap(*this).
Returns: *this.