I need to provide the user with a list of all available primitive types, and I wondered if Enum is in the .net library that has all the primitive types, so I don't need to create it.
The closest you will be System.TypeCode .
Not a listing, but:
var primitives = typeof(int).Assembly.GetTypes() .Where(type => type.IsPrimitive).ToArray();
No, there is no such listing.