Help about Template and class inheritance

[Heromyth via Digitalmars-d-learn]

Here is a sample code

```d
import std.stdio;
class Future(T)
{
        T result;

        this(T r) {
                this.result = r;
        }
}

interface IExecutorService {
        // Future!(T) submit(T)(T result);  // can't be implemented
}

abstract class ExecutorService : IExecutorService {
         Future!(T) submit(T)(T result) {
                return new Future!(T)(result);
        }
}

class ThreadPoolExecutor : ExecutorService {
        // alias submit = ExecutorService.submit;
        
        // override Future!(T) submit(T)(T result) { // can't override it
        //      return new Future!(T)(result + 10);
        // }
}

void main()
{
        ThreadPoolExecutor service = new ThreadPoolExecutor();
        ExecutorService serviceBase = service;
        IExecutorService serviceInterface = service;

        Future!(int) f = service.submit!int(12);
        writeln(f.result);
        
        f = serviceBase.submit!int(12);
        writeln(f.result);

        // f = serviceInterface.submit!int(12);
        // writeln(f.result);
}

```

The **submit** can't be defined in D as done in Java. See also 
(search for exchangeMessageVectorsAsync):

https://www.programcreek.com/java-api-examples/?code=aarmea/noise/noise-master/app/src/main/java/com/alternativeinfrastructures/noise/sync/StreamSync.java

So, is there a better way to do this in D?
Any suggestions are welcome.
Thanks.