20 General utilities library [utilities]

20.9 Function objects [function.objects]

20.9.3 Class template reference_wrapper [refwrap]

20.9.3.1 reference_wrapper construct/copy/destroy [refwrap.const]

reference_wrapper(T& t) noexcept;

Effects: Constructs a reference_wrapper object that stores a reference to t.

reference_wrapper(const reference_wrapper& x) noexcept;

Effects: Constructs a reference_wrapper object that stores a reference to x.get().