Type parameter declaration must be an identifier not a type

Question

There is a base class which has one method of generic type and I am sure that in my derived I will be returning a string. This is my code:

public abstract cl         


        

Answer 1

You cannot override a generic method with a concrete implementation; that's not how generics work. The Extended class must be able to handle calls to GetSomething() for example.

In other words, the signature for an overriding method must be identical to the method it is overriding. By specifying a concrete generic implementation of the method, you change its signature.

Consider using this approach:

public override T GetSomething()
{
    if (typeof(T) == typeof(string))
        return string.Empty;

    return base.GetSomething();
}

Note that the JIT should optimize away the conditional when compiling a particular instantiation of this method. (If it doesn't then it's not a very good JIT!)

(The syntax for your override is technically correct, but fails for other reasons as well. For example, you can't use the keyword string as a generic parameter name. And if you could, your code still wouldn't do what you want, nor would it compile, since the compiler would be unable to find a method with that signature on a supertype.)