version(deprecated)?

[Johannes Pfau]

Am Mon, 05 Nov 2012 10:48:47 +0100
schrieb "monarch_dodra" <monarchdodra at gmail.com>:

> On Monday, 5 November 2012 at 08:53:48 UTC, Johannes Pfau wrote:
> > Am Sun, 04 Nov 2012 16:48:26 +0100
> > schrieb "monarch_dodra" <monarchdodra at gmail.com>:
> >
> >> I'm wondering if there is a way to know you are in deprecated 
> >> mode or not?
> >> 
> >> The deprecated attribute is great, because it gives a clear 
> >> compile error (as opposed to a static if, which just hides the 
> >> function completely).
> >> 
> >> But the attribute alone is not enough: I have a class with a 
> >> deprecated method, which consumes a book-keeping attribute: 
> >> Not only will this attribute exist even though it has become 
> >> useless, but the other functions will keep updating this 
> >> attribute, even though it has no more consumers.
> >> 
> >> What's more, I'd still want to unittest that function, but 
> >> obviously, only when compiled in "-unittest -d".
> >> 
> >> So I have a problem.
> >> 
> >> --------
> >> Finding out if the compilation mode is deprecated is easy 
> >> enough:
> >> 
> >> //----
> >> deprecated @property void deprecateExists(){}
> >> enum deprecatedActive = is(typeof(deprecateExists));
> >> //----
> >> 
> >> The thing is it's kind of dirty, and I wouldn't want to have 
> >> to copy paste this in all of my modules, just to know whether 
> >> or not deprecation is active...
> >> 
> >> 
> >> --------
> >> We've currently implemented "version(assert)" and 
> >> "version(debug)". Do you think we should request having a 
> >> "version(deprecated)"? I think it would be very helpful. 
> >> Thoughts?
> >> 
> >> 
> >
> > As deprecated now allows optional messages some folks have 
> > suggested to
> > make deprecated behave like in other languages: Warn if 
> > something
> > deprecated is used, do not print warnings if compiling with
> > -deprecated.
> > This would conflict with your proposed usage of 
> > version(deprecated).
> 
> Is that even possible? I mean, if I deprecate R.index, then what 
> is the value of isRandomAccessRange!R?
Always true, whether compiled with -deprecated or without.

> If I call algorithm 
> "find(r1, r2);", then will I get a message I'm using a deprecated 
> branch?
Yes, IIRC that's how it's supposed to work. It would leave all code in
but warn as soon as it's used. But for generic code which could use
both deprecated and non-deprecated branches that would indeed be
annoying. I'm not sure if anyone really thought this through.

> Wouldn't the proposal be better served as:
> -- : Deprecated stuff just can't be used
> -d : You can use deprecated stuff, and you get no warning 
> whatsoever
> -dw : You can use deprecated stuff, but are served with a warning
> 
> In that context, we'd keep a clear [w|w/o] deprecated, and my 
> proposal would not conflict either.

Probably, I'm not sure as I personally don't have any problems with the
current deprecated behavior. Somebody else would have to chime in.