public bool Equals(SegmentedHashSet <T>?x, SegmentedHashSet <T>?y)
{
// If they're the exact same instance, they're equal.
if (ReferenceEquals(x, y))
{
return(true);
}
// They're not both null, so if either is null, they're not equal.
if (x == null || y == null)
{
return(false);
}
var defaultComparer = EqualityComparer <T> .Default;
// If both sets use the same comparer, they're equal if they're the same
// size and one is a "subset" of the other.
if (SegmentedHashSet <T> .EqualityComparersAreEqual(x, y))
{
return(x.Count == y.Count && y.IsSubsetOfHashSetWithSameComparer(x));
}
// Otherwise, do an O(N^2) match.
// 🐛 This is non-symmetrical, but matches original: https://github.com/dotnet/runtime/issues/69218
foreach (var yi in y)
{
var found = false;
foreach (var xi in x)
{
if (defaultComparer.Equals(yi, xi))
{
found = true;
break;
}
}
if (!found)
{
return(false);
}
}
return(true);
}