template<typename T>

friend class weak_intrusive_ptr;

static_assert(std::is_base_of<ref_counted, Base>::value,

"Base needs to be derived from ref_counted");

protected:

typedef enable_weak_ptr combined_type;

template<typename... Ts>

enable_weak_ptr(Ts&&... args)

: Base(std::forward<Ts>(args)...)

, m_anchor(new weak_ptr_anchor(this)) { }

void request_deletion() {

if (m_anchor->try_expire()) delete this;

}

private:

inline intrusive_ptr<weak_ptr_anchor> get_weak_ptr_anchor() const {

return m_anchor;

}

intrusive_ptr<weak_ptr_anchor> m_anchor;