C#: Preferred pattern for functions requiring arguments that implement two interfaces
- by JS Bangs
The argument to my function f() must implement two different interfaces that are not related to each other by inheritance, IFoo and IBar. I know of two different ways of doing this. The first is to declare an empty interface that inherits from both:
public interface IFooBar : IFoo, IBar
{
// nothing to see here
}
public int f(IFooBar arg)
{
// etc.
}
This, of course, requires that the classes declare themselves as implementing IFooBar rather than IFoo and IBar separately.
The second way is to make f() generic with a constraint:
public int f<T>(T arg) where T : IFoo, IBar
{
// etc.
}
Which of these do you prefer, and why? Are there any non-obvious advantages or disadvantages to each?