std::indirect_unary_predicate - std::indirect_unary_predicate
Defined in header <iterator>
template<class F, class I>
concept indirect_unary_predicate =
std::indirectly_readable<I> &&
std::copy_constructible<F> && (since C++20)
std::predicate<F&, std::iter_value_t<I>&> &&
std::predicate<F&, std::iter_reference_t<I>> &&
std::predicate<F&, std::iter_common_reference_t<I>>;
The concept indirect_unary_predicate specifies requirements for algorithms
that call
unary predicates as their arguments. The key difference between this concept
and
std::predicate is that it is applied to the type that I references, rather
than I
itself.
Semantic requirements
F and I model indirect_unary_predicate only if all concepts it subsumes are
modeled.