public static IEquatable <T> AsEquatable <T>([CanBeNull] T obj, [NotNull] Func <T, T, bool> equals)
{
if (equals == null)
{
throw new ArgumentNullException(nameof(equals));
}
return(new EquatableAdapter <T>(obj, EqualityComparerFactory <T> .Create(equals)));
}
public static IEqualityComparer <T> Create <TProjection>(Func <T, TProjection> projection)
{
var comparer = EqualityComparer <TProjection> .Default;
return(EqualityComparerFactory <T> .Create(
getHashCode : obj => comparer.GetHashCode(projection(obj)),
equals : (x, y) => comparer.Equals(projection(x), projection(y))
));
}
static ImmutableKeySet()
{
Comparer = EqualityComparerFactory <IImmutableSet <TKey> > .Create((left, right) => left.Overlaps(right) || (left.Empty() && right.Empty()));
}