• Chris (24/24) Jul 30 2013 I don't know if this has been raised before. I compiled an old
• John Colvin (3/28) Jul 30 2013 This has been discussed recently on the forums, can't remember
• bearophile (5/7) Jul 30 2013 Take a look at Bugzilla, and if you don't find this missed

"Chris" <wendlec tcd.ie> writes:

I don't know if this has been raised before. I compiled an old 
program which has a foreach loop like this:

foreach(i; 0..10) {
   if (condition) {
     i--; // deprecated
   }
}

dmd 2.063 compiled it without giving me any deprecation warning, 
but the results were screwed up big time in the program. The loop 
didn't work as expected. ldc2 gave me this hint:

Deprecation: variable modified in foreach body requires ref 
storage class

So I changed the loop to

foreach(ref i; 0..10) {
   if (condition) {
     i--;
   }
}

and it worked fine in both versions, dmd and ldc2. Mind you, the 
ldc2 compiled version of the program worked correctly with the 
deprecated code too. Only the dmd version didn't, although it 
didn't complain at compile time.

But maybe this is a well known issue, I haven't checked all 
issues yet.

"John Colvin" <john.loughran.colvin gmail.com> writes:

On Tuesday, 30 July 2013 at 14:27:18 UTC, Chris wrote:
 I don't know if this has been raised before. I compiled an old 
 program which has a foreach loop like this:

 foreach(i; 0..10) {
   if (condition) {
     i--; // deprecated
   }
 }

 dmd 2.063 compiled it without giving me any deprecation 
 warning, but the results were screwed up big time in the 
 program. The loop didn't work as expected. ldc2 gave me this 
 hint:

 Deprecation: variable modified in foreach body requires ref 
 storage class

 So I changed the loop to

 foreach(ref i; 0..10) {
   if (condition) {
     i--;
   }
 }

 and it worked fine in both versions, dmd and ldc2. Mind you, 
 the ldc2 compiled version of the program worked correctly with 
 the deprecated code too. Only the dmd version didn't, although 
 it didn't complain at compile time.

 But maybe this is a well known issue, I haven't checked all 
 issues yet.

This has been discussed recently on the forums, can't remember 
where. The ldc hint is correct IIRC

"bearophile" <bearophileHUGS lycos.com> writes:

Chris:

 But maybe this is a well known issue, I haven't checked all 
 issues yet.

Take a look at Bugzilla, and if you don't find this missed 
warning, then I suggest to file it.

Bye,
bearophile