Re: Cannot put delegate in interface - why not?

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Jon Skeet [C# MVP] wrote:
atwomey@xxxxxxxxx wrote:
When I try and place a delegate in an interface, like this :

public interface ITest {
double foo();
delegate void bar();
}

I get an error "delegates cannot declare types". What is it about a
delegate that makes it incompatible in an interface. I know that an
interface cannot have any implementation - is there some implementation
detail in a delegate that I don't know about?

You've tried to do something like:

public interface ITest
{
public class Foo
{
}
}

Declaring a delegate is declaring a type, which can't be part of an
interface. You should declare the delegate itself elsewhere - you can
have a member of the type which *uses* the delegate, but that's a
different matter.

Jon

Thanks for your replies - I think my question is : is the delgate a
type because it inherits from System.Delgates, even though the delegate
itself is not instantiated? I always thought of a delegate as a
"function pointer", but it's also a class and therefore a type.

.

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