C# Equivalent of Java IdentityHashMap

Question

As far as i know, there is no direct equivalent in C#. My current idea is to use a Dictionary with a custom IEqualityComparer, that checks for reference equality.

However, this seems to lose the advantage gained by hashing. Is there a way to get an individual hashcode out of every different object? Or is this impossible and I should use some other approach?

Answer 1

You can use RuntimeHelpers.GetHashCode(object) which calls object.GetHashCode() non-virtually - this is the equivalent of System.identityHashcode in Java. I think that's what you're after. So your IEqualityComparer would just use that for hashing and object.ReferenceEquals for equality.