From cppreference.com
template<classF,class...Args>conceptpredicate=std::regular_invocable<F,Args...>&&boolean-testable<std::invoke_result_t<F,Args...>>;(since C++20)The concept std::predicate<F,Args...> specifies that F is a predicate that accepts arguments whose types and value categories are encoded by Args..., i.e., it can be invoked with these arguments to produce a
result.
Note that
requires the invocation to not modify either the callable object or the arguments and be
.
Equality preservation
Expressions declared in
of the standard library concepts are required to be
(except where stated otherwise).
References
C++23 standard (ISO/IEC 14882:2024):
18.7.4 Concept predicate [concept.predicate]
C++20 standard (ISO/IEC 14882:2020):
18.7.4 Concept predicate [concept.predicate]