On 1/1/11 9:41 AM, Philippe Sigaud wrote:
On Sat, Jan 1, 2011 at 15:52, spir<[email protected]> wrote:
On Sat, 1 Jan 2011 09:56:25 +0100
Philippe Sigaud<[email protected]> 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
