How to identify if a Type is a custom struct?

Question

For a Type, there is a property IsClass, but how to know a Type is a struct?

Sorry, I have to add some more information.

1. I am using C#.
2. Although IsValueType is a necessary condition, it is obviously not enough. For an Integer is a value type also.

Answer 1

t.IsValueType && !t.IsPrimitive && !t.IsEnum;