• frame (8/8) May 28 2022 Is there a compiler switch to catch this kind of error?
• matheus (9/18) May 29 2022 Well I don't know about this, but of course I think (That if not)
• bauss (2/11) May 30 2022 Good luck convincing Walter that this is a mistake :)
• frame (11/12) May 30 2022 Well, I'm not talking about this is a mistake, just a C-thing I
• matheus (7/8) May 30 2022 I don't think this is a matter of convincing or changing the
• Dom Disc (9/18) May 30 2022 We have a solution for this problem in bugzilla:

frame <frame86 live.com> writes:

Is there a compiler switch to catch this kind of error?

```d
ulong v = 1;
writeln(v > -1);
```

IMHO the compiler should bail a warning if it sees a logic 
comparison between signed and unsigned / different integer sizes. 
There is 50% chance that a implicit conversion was not intended.

matheus <matheus gmail.com> writes:

On Sunday, 29 May 2022 at 01:35:23 UTC, frame wrote:
 Is there a compiler switch to catch this kind of error?

 ```d
 ulong v = 1;
 writeln(v > -1);
 ```

 IMHO the compiler should bail a warning if it sees a logic 
 comparison between signed and unsigned / different integer 
 sizes. There is 50% chance that a implicit conversion was not 
 intended.

Well I don't know about this, but of course I think (That if not) 
we should have at least a flag like we have with GCC (-Wextra).

Searching about I found in this topic: 
https://forum.dlang.org/post/hhpacodmcibejatqzdfg forum.dlang.org

"Good luck adding a warning into DMD. After years there still 
isn't a warning for unsigned/signed comparisons."

This is from 2017, so let's wait for experienced weighting in.

Matheus.

bauss <jj_1337 live.dk> writes:

On Sunday, 29 May 2022 at 01:35:23 UTC, frame wrote:
 Is there a compiler switch to catch this kind of error?

 ```d
 ulong v = 1;
 writeln(v > -1);
 ```

 IMHO the compiler should bail a warning if it sees a logic 
 comparison between signed and unsigned / different integer 
 sizes. There is 50% chance that a implicit conversion was not 
 intended.

Good luck convincing Walter that this is a mistake :)

frame <frame86 live.com> writes:

On Monday, 30 May 2022 at 13:15:12 UTC, bauss wrote:

 Good luck convincing Walter that this is a mistake :)

Well, I'm not talking about this is a mistake, just a C-thing I 
think. I wouldn't even ask him about that since it's in the spec.

If I could I would just clone a DMD build, disable output of the 
binary and just add flags to analyze this and other things to 
check wanted by the community.

Just a tool to check for additional bugs running before release - 
that of course would produce also false positives and should not 
be in the official compiler. But I'm far too unexperienced to 
understand the compiler and implement this - I wonder if anyone 
else ever had this idea?

matheus <matheus gmail.com> writes:

On Monday, 30 May 2022 at 13:15:12 UTC, bauss wrote:
 Good luck convincing Walter that this is a mistake :)

I don't think this is a matter of convincing or changing the 
behavior, I think that a flag for this case (If not exist) should 
be added as a warning.

A language where some people use to spread the phrase "D as 
better C" should at least have this as flag/warning too.

Matheus.

Dom Disc <dominikus scherkl.de> writes:

On Sunday, 29 May 2022 at 01:35:23 UTC, frame wrote:
 Is there a compiler switch to catch this kind of error?

 ```d
 ulong v = 1;
 writeln(v > -1);
 ```

 IMHO the compiler should bail a warning if it sees a logic 
 comparison between signed and unsigned / different integer 
 sizes. There is 50% chance that a implicit conversion was not 
 intended.

We have a solution for this problem in bugzilla:
https://issues.dlang.org/show_bug.cgi?id=259

This would allow for the above compare to simply work with all 
integer types signed or unsigned and produce always the correct 
result.

It was rejected because it would break old code that rely on this 
misbehaviour (and even worse: the behaviour would be different 
from what C does, oh my god!!)