Am Sat, 14 Dec 2013 16:38:20 +0100 schrieb "Joseph Rushton Wakeling" <joseph.wakel...@webdrake.net>:
> On Saturday, 14 December 2013 at 15:26:36 UTC, Jakob Ovrum wrote: > > On Friday, 13 December 2013 at 14:52:32 UTC, Marco Leise wrote: > >> Most non-trivial ranges do the actual work in `popFront()' and > >> return a cached value from `front'. It has been argued as a > >> design quirk, that this in general leads to: > > > > Really? I've never seen that particular pattern. I always just > > see the initial element being computed when the range is > > initialized, e.g. in a constructor or a constructor helper > > function. > > I don't know about "most non-trivial ranges" but it is a pattern > that shows up when you have a struct that cannot be guaranteed to > be properly initialized upon creation -- which is a common > situation because structs don't allow a default constructor > this(). I probably over-dramatized this from my own experience and a recent thread in digitalmars.D. Looking at some old code of mine I actually call .popFront() in a ctor where I thought I used a boolean flag. It's not a big deal in any case. -- Marco
