using System;

​

public interface IInput

{

}

​

public interface IOutput

{

}

​

public interface IProvider<Tin, Tout>

    where Tin : IInput where Tout : IOutput

{

        void SayHello();

}

​

public class Input : IInput

{

}

​

public class Output : IOutput

{

}

​

public class Provider : IProvider<Input, Output>

{

    public void SayHello()

    {

        Console.WriteLine("Hello!");

    }

}

​

public static class ProviderFactory

{

    public static IProvider<TInput, TOutput> GetProvider<TInput, TOutput>()

    where TInput : IInput where TOutput : IOutput

    {

        return (IProvider<TInput, TOutput>)new Provider();

    }

}

​

public class Program

{

    public static void Main()

    {

        IProvider<Input, Output> provider = ProviderFactory.GetProvider<Input, Output>();

        provider.SayHello();

    }

}