2011/4/1 Regan Heath <re...@netmail.co.nz>: > On Mon, 28 Mar 2011 17:54:29 +0100, bearophile <bearophileh...@lycps.com> > wrote: >> >> Steven Schveighoffer: >> >>> So essentially, you are getting the same thing, but using [] is slower. >> >> It seems I was right then, thank you and Kagamin for the answers. > > This may be slightly OT but I just wanted to raise the point that > conceptually it's nice to be able to express (exists but is empty) and (does > not exist). Pointers/references have null as a (does not exist) "value" and > this is incredibly useful. Try doing the same thing with 'int' .. it > requires you either use int* or pass an additional boolean to indicate > existence.. yuck. > > I'd suggest if someone types '[]' they mean (exists but is empty) and if > they type 'null' they mean (does not exist) and they may be relying on the > .ptr value to differentiate these cases, which is useful. If you're not > interested in the difference, and you need performance, you simply use > 'null'. Everybody is happy. :) > > R >
For associative arrays it certainly would be nice to be able to do something like string[string] options = [:]; so that functions can manipulate an empty aa without using ref. Torarin
