Sets in

About Sets

A set is a collection of unique values. The default .NET implementation of a set is the HashSet<T>.

The HashSet class uses each element's GetHashCode() method.

By default, the GetHashCode() implementation for reference types returns a hash of its memory location. This means that different reference type objects will have a different hash code (this is known as reference equality). Value types by default return a hash of their fields/properties. This means that different value type objects with the same field/property values will have the same hash code (this is known as structural equality).

You can override the GetHashCode() implementation on your own classes, which you could use to have a reference type have structural equality.