• DLearner (14/14) Aug 16 2021 Hi
• rikki cattermole (2/2) Aug 16 2021 No.
• jfondren (6/20) Aug 16 2021 dmd is anti-warning, so it'd have to be an error, which might be
• user1234 (5/8) Aug 16 2021 No in DMD but you can use
• russhy (8/22) Aug 16 2021 Hi, not compiler, but with dscanner it is possible, in fact with

DLearner <bmqazwsx123 gmail.com> writes:

Hi

Please see code below:
```
void main() {

    import std.stdio;

    size_t i;
    size_t j;

    i = 5;

    writeln("i = ",i);

}

```

Is there a compiler option that would warn that variable 'j' is 
defined but not used?

Best regards

rikki cattermole <rikki cattermole.co.nz> writes:

No.

https://github.com/dlang-community/D-Scanner#implemented-checks

jfondren <julian.fondren gmail.com> writes:

On Monday, 16 August 2021 at 14:14:27 UTC, DLearner wrote:
 Hi

 Please see code below:
 ```
 void main() {

    import std.stdio;

    size_t i;
    size_t j;

    i = 5;

    writeln("i = ",i);

 }

 ```

 Is there a compiler option that would warn that variable 'j' is 
 defined but not used?

 Best regards

dmd is anti-warning, so it'd have to be an error, which might be 
more annoying than it's worth. `dscanner --report thefile.d` 
includes "Variable j is never modified and could have been 
declared const or immutable." and "Variable j is never used." as 
issues, with line and column numbers.

user1234 <user1234 12.de> writes:

On Monday, 16 August 2021 at 14:14:27 UTC, DLearner wrote:
 Is there a compiler option that would warn that variable 'j' is 
 defined but not used?

 Best regards

No in DMD but you can use 
[D-Scanner](https://code.dlang.org/packages/dscanner) for that. 
The check works reasonably as long as the variables are not 
introduced by `mixin()` or metaprog.

russhy <russhy gmail.com> writes:

On Monday, 16 August 2021 at 14:14:27 UTC, DLearner wrote:
 Hi

 Please see code below:
 ```
 void main() {

    import std.stdio;

    size_t i;
    size_t j;

    i = 5;

    writeln("i = ",i);

 }

 ```

 Is there a compiler option that would warn that variable 'j' is 
 defined but not used?

 Best regards

Hi, not compiler, but with dscanner it is possible, in fact with 
the code-d vscode extension, you get that out of the box with 
visual hints!

Take a look at this screenshot:

https://i.imgur.com/TGkgY3e.png

If you click on the line, it jumps automatically to the right 
line, very nice tooling