How do I implement IEnumerable in my Dictionary wrapper class that implements IEnumerable?

Question

I\'m trying to create a wrapper for a Dictionary.

Dictionary implements IEnumerable

Answer 1

The problem is that there is no such thing as return type covariance in .NET - IEnumerator M() and IEnumerator<Foo> M() are completely different methods.

The workaround is that you have to implement the non-generic version explicitly:

System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
{
    // this calls the IEnumerator<Foo> GetEnumerator method
    // as explicit method implementations aren't used for method resolution in C#
    // polymorphism (IEnumerator<T> implements IEnumerator)
    // ensures this is type-safe
    return GetEnumerator();
}