Partially instantiating templates?

[Magnus Lie Hetland]

On 2011-02-01 12:37:05 +0100, Simen kjaeraas said:

> Magnus Lie Hetland <magnus at hetland.org> wrote:
> 
>> Hm. Just to make sure this *is* a bug, and I'm not just being a dumbass 
>> ... this is a tiny program that illustrates the problem (i.e., gives 
>> the error above). Perhaps the use of a local function here really is 
>> prohibited...?
> 
> Maybe it is. It really shouldn't be, though. If this is not a bug, then
> Walter has a bug for not accepting this as a bug. :p

Hehe :)

Sort of related (though perhaps only remotely) is the following, which 
won't compile (Error: static assert "Bad unary function: f(a) for type 
int"):

  import std.functional, std.stdio;
  int f(int x) {return x;}
  void main() {
      alias unaryFun!("f(a)") g;
      writeln(g(3));
  }

It may not be related -- but I've been trying to use the string 
representation instead of lambda in some places, and I thought maybe a 
similar name lookup problem may be present in the unaryFun template? 
(The detauls of the implementation are a bit beyond me at the moment...)

Maybe there's an unstated restriction against using functions in the 
unaryFun string parameter (at least I couldn't find it in the docs) -- 
but ... there is the following example in the docs for std.algorithms:

  sort!("hashFun(a) < hashFun(b)")(array);

So it would seem like this *should* work?

-- 
Magnus Lie Hetland
http://hetland.org