Adding constraints to an interface property

Question

I'm writing an interface and I want to declare a property that returns a generic collection. The elements of the collection should implement an interface. Is this possible and, if so, what is the syntax.

This doesn't compile, what's the right way to do this?

interface IHouse
{
    IEnumerable<T> Bedrooms { get; } where T : IRoom
}

Thanks

Answer 1

You have to mark the interface as generic as well:

interface IHouse<T> where T : IRoom
{
    IEnumerable<T> Bedrooms { get; } 
}

Answer 2

Why use generics? Just do:

interface IHouse
{
    IEnumerable<IRoom> Bedrooms { get; } 
}

This is cleaner, and since you're already restricting to the interface, it will act nearly identically.

Answer 3

Generic is for classes and methods, not properties. If a class/interface is generic, then you can use the type in the property. I agree with Reed's solution.