element_type* get() const noexcept;
T& operator*() const noexcept;
Remarks: When T is an array type or cv void, it is unspecified whether this member function is declared. If it is declared, it is unspecified what its return type is, except that the declaration (although not necessarily the definition) of the function shall be well formed.
T* operator->() const noexcept;
Remarks: When T is an array type, it is unspecified whether this member function is declared. If it is declared, it is unspecified what its return type is, except that the declaration (although not necessarily the definition) of the function shall be well formed.
element_type& operator[](ptrdiff_t i) const;
Remarks: When T is not an array type, it is unspecified whether this member function is declared. If it is declared, it is unspecified what its return type is, except that the declaration (although not necessarily the definition) of the function shall be well formed.
long use_count() const noexcept;
Returns: The number of shared_ptr objects, *this included, that share ownership with *this, or 0 when *this is empty.
[ Note: When multiple threads can affect the return value of use_count(), the result should be treated as approximate. In particular, use_count() == 1 does not imply that accesses through a previously destroyed shared_ptr have in any sense completed. — end note ]
explicit operator bool() const noexcept;
template<class U> bool owner_before(const shared_ptr<U>& b) const noexcept;
template<class U> bool owner_before(const weak_ptr<U>& b) const noexcept;
Returns: An unspecified value such that
x.owner_before(y) defines a strict weak ordering as defined in [alg.sorting];
under the equivalence relation defined by owner_before, !a.owner_before(b) && !b.owner_before(a), two shared_ptr or weak_ptr instances are equivalent if and only if they share ownership or are both empty.