How to best implement Equals for custom types?

Question

Say for a Point2 class, and the following Equals:

public override bool Equals ( object obj )

public bool Equals ( Point2 obj )

This is the

Answer 1

• Define what the identity means.. if reference identity then the default inherited equals will work.
• If a value type (and thus value identity) you need to define.
• If a class type, but has value semantics then define.

Likely you want to both override Equals(object) and define Equals(MyType) because the latter avoids boxing. And override the equality operator.

.NET Framework Guidelines book (2nd ed) has more coverage.