Re: Generics and selection based on type

["Björn Persson" <spam-away@nowhere.nil>]

Maciej Sobczak wrote:

> I would like to write a generic function that returns the string
> representation of its parameter, which can be a number or a string.

[...]

> For this, it would be good to be able to select the implementation of
> To_String based on what the type is. If it's numeric - the 'Image
> attribute can be used. If it's already String - just return the
> argument. And so on.
> 
> Is it possible?

I think that's impossible. You can only do things with the parameter that
you can do with all types that the generic function can be instantiated
with. I also don't see the point. Why don't you simply write a set of
overloaded functions? It won't take more work or more code, as you'll have
to write all the different implementations either way. Generics are for
cases where you can use the same implementation for different types.

-- 
Bj�rn Persson                              PGP key A88682FD
                   omb jor ers @sv ge.
                   r o.b n.p son eri nu