Walter Bright, el 6 de November a las 20:19 me escribiste: > On 11/6/2012 7:52 PM, bearophile wrote: > >Walter Bright: > > > >>But I'm not sure at this point if that is the right thing to do. > > > >Why? > > D was fortunate in having 10 years of experience with C++'s > exception system to learn from. We don't have that with UDAs.
What? UDAs has been for quite a long time out in the wild, just not in C++. > >[If you decide to restrict UDAs, then later it will be easy to extend them, > >it > >will not break code. While doing the opposite break code. It's you the one > >that > >has taught me to design things this way :-) ] > > It's a good point, but I have no experience with UDAs. OK, that's another thing. And maybe a reason for listening to people having more experience with UDAs than you. For me the analogy with Exceptions is pretty good. The issues an conveniences of throwing anything or annotating a symbol with anything instead of just type are pretty much the same. I only see functions making sense to be accepted as annotations too (that's what Python do with annotations, @annotation symbol is the same as symbol = annotation(symbol), but is quite a different language). --
