dropping parentheses on template instantiation

[KennyTM~]

Ary Borenszweig wrote:
> Andrei Alexandrescu escribió:
>> Denis Koroskin wrote:
>>> On Sun, 05 Oct 2008 22:18:26 +0400, Andrei Alexandrescu 
>>> <SeeWebsiteForEmail at erdani.org> wrote:
>>>
>>>> I just realized something different. After making an informal review 
>>>> of some code, I saw that a large percentage of template 
>>>> instantiations only need ONE argument.
>>>>
>>>> This makes me think, with the old "!" notation, parentheses could be 
>>>> dropped entirely without prejudice:
>>>>
>>>> auto covariance = Matrix!real(n, n);
>>>> auto normalized = SparseVector!double(n);
>>>>
>>>> and so on.
>>>>
>>>> To the unbridled joy of the enemies of the Sad Pirate, the dot won't 
>>>> work for template instantiation because without the parentheses it 
>>>> DOES engender ambiguity.
>>>>
>>>> Now say we take the following route:
>>>>
>>>> 1) We find something different from shouting
>>>>
>>>> 2) We drop the parentheses for 1 argument
>>>>
>>>> That sounds like a possible winner. In this case the "#" becomes 
>>>> considerably more attractive, in fact very attractive exactly 
>>>> because it looks unlike any letter:
>>>>
>>>> auto covariance = Matrix#real(n, n);
>>>> auto normalized = SparseVector#double(n);
>>>>
>>>> Ideas?
>>>>
>>>>
>>>> Andrei
>>>>
>>>> P.S. The Sad Pirate is the emoticon
>>>>
>>>> .(
>>>>
>>>> It doesn't have an eye and is sad, too.
>>>
>>> Just to clarify things: Do you propose moving the first template 
>>> argument outside of the parentheses *or* ditching them iff there is 
>>> only one parameter? I mean, what does the original code look like, 
>>> because there is ambiguaty in your statement (to me):
>>
>> Ditch parens if there's only one argument. In that case the extra 
>> character becomes an enabling asset, not a liability.
>>
>>> const int n = 42;
>>> auto covariance = Matrix!(real, n, n); <-> auto covariance = 
>>> Matrix#real(n,n);
>>>
>>> *or*
>>>
>>> auto covariance = Matrix!(real)(n, n); <-> auto covariance = 
>>> Matrix#real(n,n);
>>
>> The latter.
>>
>>> Other than that Vector at real or Vector#real both sound good!
>>
>> I agree. In fact "Vector at real" sounds like a good way of talking 
>> about templates instead of "Vector instantiated with real". One reason 
>> for which I think "this" is a poor choice (as opposed to e.g. "self") 
>> is that it's very hard to talk about it.
> 
> I like Vector at real. Also: HashMap@(Key, Value) looks nice to me. The 
> only thing is that in spanish keboards, I have to do alt-gr + Q to get 
> one @ :-P

It seems that

Stack!int
Stack at int
Stack#int

are the only choices we're left with. All others are either binary 
operators, delimiters or some kind of parenthesis. But frankly speaking 
all of these characters are not very pretty :/