• =?iso-8859-1?Q?Robert_M._M=FCnch?= (17/17) Jan 31 2016 I have:
• Chris Wright (17/26) Jan 31 2016 This expands to:

=?iso-8859-1?Q?Robert_M._M=FCnch?= <robert.muench saphirion.com> writes:

I have:

class OperatorV(T) : Value {
  T impl;

  this(T impl) {
    this.impl = impl;
  }
...

and use it like this: makeOperator((IntV a, IntV b) => new IntV(a.num + 
b.num));

Now I want to do: opWord.get() returns a Value

OperatorV *op = cast(OperatorV*)(opWord.get());

and get: Error: class app.OperatorV(T) is used as a type

Hmm... any idea? Don't know how to carry the template stuff around.

-- 
Robert M. Münch
http://www.saphirion.com
smarter | better | faster

Chris Wright <dhasenan gmail.com> writes:

On Sun, 31 Jan 2016 19:59:01 +0100, Robert M. Münch wrote:

 I have:
 
 class OperatorV(T) : Value {
   T impl;
 
   this(T impl) {
     this.impl = impl;
   }
 ...

This expands to:

template OperatorV(T) {
  class OperatorV {
    ...
  }
}

If you're just typing `OperatorV` with no template arguments, you're 
referring to the template itself.

There's not necessarily any relationship between two instantiations of a 
template with different arguments. You could write it so that OperatorV!
int and OperatorV!string have entirely different sets of methods, 
constructors, and fields.

Because of that, the compiler doesn't create a base class for you 
automatically. But you can do it yourself:

class BaseOperator {}  // or interface, or abstract class
class OperatorV(T) : BaseOperator {}