While we were discussing lambda syntax..

[Philippe Sigaud]

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.