> -----Original Message----- > From: Martin Sebor [mailto:[EMAIL PROTECTED] > Sent: Friday, May 30, 2008 3:05 PM > To: dev@stdcxx.apache.org > Subject: Re: type_traits progress > > Travis Vitek wrote: > > > > > > Eric Lemings wrote: > >>> Travis Vitek wrote: > >>> > >> ... > >>> As an example, the array traits above are all closely related > >>> and their > >>> implementations are similar. There are five traits, and > those traits > >>> span three sections of the standard. > >>> > >>> I'm open to doing some type of grouping, we just need to > >>> understand how > >>> we want to group them and then how we want to name the files. > >> The term you're looking for is cohesion. :) I kinda like this > >> organization. Couple things though. > >> > >> Why put __rw_decay, a single helper trait in its own header? > > > > Well decay deals with conversion from array to pointer and > function to > > function pointer conversions. I can't necessarily put it into both > > _meta_array.h and _meta_func.h, so I figured it would be > best to put it > > into a file by itself. > > FWIW, I see no problem with bundling groups of traits together > even if some of them are unlikely to be used in the rest of the > lib, just as long as their implementation isn't too big (i.e., > doesn't bloat translation units and unnecessarily increase > compilation time).
Well when it comes to metaprogramming, there's almost always a tradeoff in these two respects. Either the translation unit size increases or compile times increase. But you're right: we should minimize both whenever possible. BTW, which of these two should be the preferred: comile-time computations (metaprogramming) or runtime processing? I would say compile-time even though that will signficantly impact us developers but I think users would prefer this since they do not build nearly as often. Brad.
