While we were discussing lambda syntax..

[Andrei Alexandrescu]

On 1/1/11 9:41 AM, Philippe Sigaud wrote:
> On Sat, Jan 1, 2011 at 15:52, spir<denis.spir at gmail.com>  wrote:
>> On Sat, 1 Jan 2011 09:56:25 +0100
>> Philippe Sigaud<philippe.sigaud at gmail.com>  wrote:
>>
>>> As I said in the docs, I got stuck at comparison operators. a<    b is
>>> automatically transformed by the compiler into a.opCmp(b)<  0.
>>> a.opCmp(b) becomes another lambda and the '<  0' part triggers another
>>> expansion, ad infinitum...
>>
>> Is this a good design choice? I mean opCmp looks like a good idea (wrapping all comparisons in a single one instead of having to implement all separatedly), but is it really one? It currently annoys me for a custom sort where what I need is just less-than. opEquals is already apart: I would vote +++ for opLessThan. Then, a programmer can get rid of opCmp alltogether (I don't mean it should be deprecated, may have uses).
>
> I don't know if it's good design or not. All I can say is that's the
> point where C++ can continue and one can have Boost::lambda. Whereas I
> was stuck.
>
> Anyway, that was a small foray into expression templates, which was
> interesting and such... But I went back to string templates. For small
> expressions, they are quite palatable. I just developed a n-args
> version of UnaryFun/BinaryFun, which was one of the most useful little
> helper I ever did in D.

Great! I recall I tried to do that a couple of years ago, but hit a few 
bugs. Could you make NaryFun into a proposal for Phobos?

Andrei