22 General utilities library [utilities]

22.10 Function objects [function.objects]

22.10.17 Polymorphic function wrappers [func.wrap] Class template function [func.wrap.func] Target access [func.wrap.func.targ]

const type_info& target_type() const noexcept;
Returns: If *this has a target of type T, typeid(T); otherwise, typeid(void).
template<class T> T* target() noexcept; template<class T> const T* target() const noexcept;
Returns: If target_type() == typeid(T) a pointer to the stored function target; otherwise a null pointer.