std::experimental::atomic_weak_ptr::is_lock_free

From cppreference.com
bool is_lock_free() const;

Checks whether the atomic operations on all objects of this type are lock-free.

Parameters

(none)

Return value

true if the atomic operations on the objects of this type are lock-free, false otherwise.

Exceptions

noexcept specification:  
noexcept
  

See also

specializes atomic operations for std::shared_ptr
(function template)