template <class F, class I>

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

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