How do I provide a default implementation in a child interface?

Question

If I have an interface IExampleInterface:

interface IExampleInterface {
    int GetValue();
}

Is there a way to provide a default implementation for GetValue() in a child interface? I.e.:

interface IExampleInterfaceChild : IExampleInterface {
    // Compiler warns that we're just name hiding here. 
    // Attempting to use 'override' keyword results in compiler error.
    int GetValue() => 123; 
}

Answer 1

After more experimentation, I found the following solution:

interface IExampleInterfaceChild : IExampleInterface {
    int IExampleInterface.GetValue() => 123; 
}

Using the name of the interface whose method it is that you're providing an implementation for is the right answer (i.e. IParentInterface.ParentMethodName() => ...).

I tested the runtime result using the following code:

class ExampleClass : IExampleInterfaceChild {
        
}

class Program {
    static void Main() {
        IExampleInterface e = new ExampleClass();

        Console.WriteLine(e.GetValue()); // Prints '123'
    }
}