export module bedrock.semantics:equivalence;

import :utility;
import :referenceable;
import :integral;

namespace br {

export template <typename T, typename U = T>
concept PartialEquivalence = requires(Unref<T> a, Unref<U> b) {
	{ a == b } -> SameAs<bool>;
	{ a != b } -> SameAs<bool>;
	{ b == a } -> SameAs<bool>;
	{ b != a } -> SameAs<bool>;
};

export template <PartialEquivalence T>
struct EquivalenceType {
	static constexpr bool is_valid = false;
};

export template <typename T>
concept Equivalence = PartialEquivalence<T> && (EquivalenceType<T>::is_valid || Integral<T>);

}  // namespace br