Cast<T>() with a Type variable

Question

I am trying to make a method to enumerate any enum, by returning a list containing each constant name and value.

Here's my code:

Type enumType = typeof(SomeEnum);
var enumConstants = 
    Enum.GetValues(enumType).
         Cast<enumType>().
         Select(x => new { Value = (int) x, Name = x.ToString() });

_{(I declare enumType in this snippet but it is in fact declared in my method signature as MyMethod(Type enumType). I am not showing my method signature because that would require to introduce some struct I am using, which is not relevant to the problem here)}

The problem is that this code does not compile and I am getting on the Cast<enumType>(). line the following error:

The type or namespace name 'enumType' could not be found (are you missing a using directive or an assembly reference?)

I don't understand how can enumType be unknown, I just declared it on the previous line!

Note that on the Enum.GetValues(enumType). line, there is no error flagged.

Am I missing something here? Is some LINQ playing tricks?

Answer 1

Generics don't allow you to pass an instance of a variable, you'll need to either use Cast<SomeEnum>(), or make the method where this code lies generic, and use something like Cast<T>().

Answer 2

This should be:

Type enumType = typeof(SomeEnum);
var enumConstants = 
    Enum.GetValues(enumType).
     Cast<SomeEnum>().
     Select(x => new { Value = (int) x, Name = x.ToString() });

The problem is the Cast<T>() call. The generic method type needs the actual type specification (SomeEnum), not a System.Type (enumType).