When should I use a struct rather than a class in C#?

Question

When should you use struct and not class in C#? My conceptual model is that structs are used in times when the item is merely a collection of value types. A way to

Answer 1

With the exception of the valuetypes that are used directly by the runtime and various others for PInvoke purposes, you should only use valuetypes in 2 scenarios.

1. When you need copy semantics.
2. When you need automatic initialization, normally in arrays of these types.