std::experimental::ranges::reference_t,std::experimental::ranges::rvalue_reference_t, (3) Linux Manual Page

std::experimental::ranges::reference_t,std::experimental::ranges::rvalue_reference_t, – std::experimental::ranges::reference_t,std::experimental::ranges::rvalue_reference_t,

Synopsis

Defined in header <experimental/ranges/iterator>

template <class T>

concept bool /*dereferenceable*/ = requires(T& t) { {*t} -> auto&&;

}; // exposition only

template< /*dereferenceable*/ T >                                    (1) (ranges TS)

using reference_t = decltype(*declval<T&>());

template< /*dereferenceable*/ T >

requires requires(T& t) { { ranges::iter_move(t) } -> auto&&; }      (2) (ranges TS)

using rvalue_reference_t =

decltype(ranges::iter_move(declval<T&>()));

template< Readable T >
using iter_common_reference_t =                                      (3) (ranges TS)

ranges::common_reference_t<ranges::reference_t<T>,
ranges::value_type_t<T>&>;

1) Obtain the reference type of a dereferenceable type T.
2) Obtain the rvalue reference type of a dereferenceable type T, that is, the return
type of ranges::iter_move.
3) Compute a Readable type’s common reference type. This is the common reference
type of its reference type and an lvalue reference to its value type.

Notes

The -> auto&& constraint checks that the type of the expression is not void.