23 General utilities library [utilities]

23.14 Function objects [function.objects]

23.14.13 Polymorphic function wrappers [func.wrap] Class template function [func.wrap.func] function 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.