sparrow::mpl::callable_type_predicate Concept Reference

Concept for callable type predicates. More...

#include <mp_utils.hpp>

Concept definition

template<class P, class T>
concept sparrow::mpl::callable_type_predicate =  std::semiregular<std::decay_t<P>>
    and (
            requires(std::decay_t<P> predicate)
            {
                { predicate(typelist<T>{}) } -> std::convertible_to<bool>;
            }
        or
            requires(std::decay_t<P> predicate)
            {
                { predicate(std::type_identity_t<T>{}) } -> std::convertible_to<bool>;
            }
        )
    

Detailed Description

Concept for callable type predicates.

This concept matches types whose instances can be called with an object representing a type to evaluate it. The object passed can be either a typelist with one element or std::type_identity_t<T>.

Template Parameters

P	Predicate type to check
T	Type to apply predicate to

Precondition

P must be semiregular

Postcondition

True if P instance can be called with type wrapper of T

auto predicate = [](auto type_wrapper) { return / some condition /; };
static_assert(callable_type_predicate<decltype(predicate), int>);

Definition at line 328 of file mp_utils.hpp.