std::experimental::ranges::IndirectUnaryPredicate

template< class F, class I >

concept bool IndirectUnaryPredicate =
    Readable<I> && CopyConstructible<F> &&
    Predicate<F&, ranges::value_type_t<I>&> &&
    Predicate<F&, ranges::reference_t<I>> &&

    Predicate<F&, ranges::iter_common_reference_t<I>>;