foo!(bar) ==> foo{bar}

[Andrei Alexandrescu]

KennyTM~ wrote:
> Andrei Alexandrescu wrote:
>> Alexander Pánek wrote:
>>> Steven Schveighoffer wrote:
>>>> "Alexander Pánek" wrote
>>>>> Steven Schveighoffer wrote:
>>>>>> Everything runs together, looks like one big word.  I think we 
>>>>>> need a full height character to represent template brackets, 
>>>>>> something with a lot of whitespace to separate it from the other 
>>>>>> characters.
>>>>> Heh... sounds like !() to me! ;)
>>>>
>>>> *gasp*  That's perfect!  I say we go with it ;)
>>>
>>> Has my vote, for sure!
>>
>> One possibility to make progress would be to keep !( but allow 
>> omitting the parens when only one argument is being passed. That way 
>> many instantiations will be helped. For example, in wake of the 
>> impending demise of complex built-ins:
>>
>> Complex!double alpha;
>> Complex!float[] data;
>>
>> That way, again, we leverage the fact that an extra symbol is needed 
>> instead of compulsively requiring it in addition of the parens.
>>
>> One nice thing about this change is that it keeps all code as it is, 
>> just lifts one restriction.
>>
>> How about that?
>>
>>
>> Andrei
> 
> vote++ for this.
> 
> But how do templates with no arguments be called? Is “T!” valid?

Offhand, that looks like it can't work, but haven't we all been wrong 
before? :o)

> If so, 
> can these ambiguity be solved first? These are minor cases, though.
> 
> (1) opCall strikes again!
> 
> class T(int n = 6) {
>         static int opCall (int z) {
>                 writefln(z);
>         return z;
>         }
>     static char init;
> }
> 
> void main() {
>     auto x = T!(4).init;
> }

This is not an opCall issue. A template can alias itself to anything. 
Consider:

template A(T = int)
{
     alias foo A; // say foo is a function
}

> (2) !is
> 
> template T() {
>     enum T = 3;
> }
> 
> void main () {
>     writeln(T!is 3);
> }

This is not a problem because "is" is a keyword.


Andrei