std::experimental::ranges:: IndirectUnaryPredicate

From cppreference.com
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 >> ;
(ranges TS)