20 General utilities library [utilities]

20.9 Function objects [function.objects]

20.9.3 Class template reference_wrapper [refwrap]

20.9.3.5 reference_wrapper helper functions [refwrap.helpers]

template <class T> reference_wrapper<T> ref(T& t) noexcept;

Returns: reference_wrapper<T>(t)

template <class T> reference_wrapper<T> ref(reference_wrapper<T> t) noexcept;

Returns: ref(t.get())

template <class T> reference_wrapper<const T> cref(const T& t) noexcept;

Returns: reference_wrapper <const T>(t)

template <class T> reference_wrapper<const T> cref(reference_wrapper<T> t) noexcept;

Returns: cref(t.get());