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[Michel Fortin]

On 2009-12-17 07:09:57 -0500, KennyTM~ <kennytm at gmail.com> said:

> On Dec 17, 09 19:44, Michel Fortin wrote:
>> On 2009-12-17 01:57:50 -0500, Pelle Månsson <pelle.mansson at gmail.com> said:
>> 
>>> On 12/17/2009 01:05 AM, Michel Fortin wrote:
>>>> Object? func(Object? o) {
>>>> writeln(o.toString());
>>>> return o;
>>>> }
>>>> 
>>>> MyObject o = func(new MyObject);
>>>> 
>>>> Here, "Object?" means Object or a derived type.
>>>> 
>>> You know, just Object means Object or a derived type. That's what
>>> inheritance is.
>> 
>> The idea is to be able to say in the function signature that the same
>> type is returned, avoiding a cast that would be unnecessary otherwise.
>> It's the same principle as for "const?", or "inout".
>> 
>> But you're right that my definition isn't very good.
> 
> T func(T)(T o);

That would work, unless you want a virtual function.

If templates were always an acceptable solution, the whole discussion 
about passing const qualifiers from the argument to the return value 
wouldn't be of any use either.


-- 
Michel Fortin
michel.fortin at michelf.com
http://michelf.com/