I have a method like public static TOut Method<TIn, TOut>(TIn in) with constraint where TIn: class, Interface<TOut>.

Do I always need to write Method<ClassIn, ClassOut>(ObjectIn); when I use it, or is there some way to make the TIn inferred by arguments so I only need to write Method<ClassOut>(ObjectIn);? The ClassOut varies from time to time so I can't write a static class for it every time.

Also, is it right that C# cannot infer types from the constraints so it is impossible to make both TIn and TOut inferred?

CodePudding user response：

Yes, you always need to specify both types. Type inference only works when you specify all the type arguments.

Yes, the C# compiler cannot infer types based on constraints. It can only infer the types based on the types you pass in as arguments.

On a side note, there is an open issue about improving type inference in this regard, however it doesn't seem to have high priority.