std::experimental::atomic_shared_ptr::atomic_shared_ptr

From cppreference.com
constexpr atomic_shared_ptr();
(1)
constexpr atomic_shared_ptr( shared_ptr<T> desired );
(2)
atomic_shared_ptr( const atomic_shared_ptr& ) = delete;
(3)

Constructs a new atomic_shared_ptr object.

1) The default constructor initializes the object to an empty state.
2) Initializes the underlying shared_ptr<T> with desired. The initialization is not atomic.
3) Atomic variables are not CopyConstructible.

Parameters

desired - value to initialize with

Exceptions

1-2)
noexcept specification:  
noexcept