[
Example 1:
struct X: public enable_shared_from_this<X> { };
int main() {
shared_ptr<X> p(new X);
shared_ptr<X> q = p->shared_from_this();
assert(p == q);
assert(p.owner_equal(q));
}
—
end example]
namespace std {
template<class T> class enable_shared_from_this {
protected:
constexpr enable_shared_from_this() noexcept;
constexpr enable_shared_from_this(const enable_shared_from_this&) noexcept;
constexpr enable_shared_from_this& operator=(const enable_shared_from_this&) noexcept;
constexpr ~enable_shared_from_this();
public:
constexpr shared_ptr<T> shared_from_this();
constexpr shared_ptr<T const> shared_from_this() const;
constexpr weak_ptr<T> weak_from_this() noexcept;
constexpr weak_ptr<T const> weak_from_this() const noexcept;
private:
mutable weak_ptr<T> weak-this;
};
}