https://issues.dlang.org/show_bug.cgi?id=7386

Iain Buclaw <ibuclaw@gdcproject.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P2                          |P1
                 CC|                            |ibuclaw@gdcproject.org

--- Comment #1 from Iain Buclaw <ibuclaw@gdcproject.org> ---
Bumping priority of this one.

--

https://issues.dlang.org/show_bug.cgi?id=7386

Dennis <dkorpel@live.nl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dkorpel@live.nl

--- Comment #2 from Dennis <dkorpel@live.nl> ---
> The compiler's evaluation seems to occur in the wrong order ("versions before static ifs" instead of "top to bottom")

This 'evaluation order' is totally underspecified and super tricky. Simply going top to bottom doesn't work since a static if can have forward references:

```
static if (x == 0) {
    version = X1;
}

version(X1) {

}

enum x = 0;
```

Even trickier:
```
static if (x == 0) {
    version = X1;
}

version(X1) {
    version = X2;
}

version(X2) {
    enum x = 0;
}
```

--

https://issues.dlang.org/show_bug.cgi?id=7386

anonymous4 <dfj1esp02@sneakemail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|rejects-valid               |spec
           Severity|major                       |enhancement

--- Comment #3 from anonymous4 <dfj1esp02@sneakemail.com> ---
It feels like version is a lightweight feature and is processed early as it
doesn't depend much on semantics of the surrounding code, while static if tends
to be processed on later stages as it needs module that passed most semantic
checks.
As a workaround the original example can simply use static if everywhere;
static if can inspect versions too: see issue 7417

--

https://issues.dlang.org/show_bug.cgi?id=7386

anonymous4 <dfj1esp02@sneakemail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|enhancement                 |minor

--

https://issues.dlang.org/show_bug.cgi?id=7386

KytoDragon <kytodragon@e.mail.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kytodragon@e.mail.de

--- Comment #4 from KytoDragon <kytodragon@e.mail.de> ---
(In reply to anonymous4 from comment #3)
> It feels like version is a lightweight feature and is processed early as it
> doesn't depend much on semantics of the surrounding code, while static if
> tends to be processed on later stages as it needs module that passed most
> semantic checks.
> As a workaround the original example can simply use static if everywhere;
> static if can inspect versions too: see issue 7417

There are few bugs related to static if (see https://issues.dlang.org/show_bug.cgi?id=20905), so replacing all versions with static if is not currently possible.

--

https://issues.dlang.org/show_bug.cgi?id=7386

--- Comment #5 from Iain Buclaw <ibuclaw@gdcproject.org> ---
Potentially very breaking, but declaring versions could be even more restrictive than it currently is.

i.e: When setting a version in a function or user defined type, you expect a compile-time error.

    Error: version `Foo` declaration must be at module level

This could be extended to `static if` as well so that we avoid all these nasty cases of will it, won't it work.  Also noting that it's currently an error to declare a version inside a `static foreach`.

---
static foreach (_; 0 .. 5) {
    version = Foo;  // Error: version `Foo` declaration must be at module level
}
---

So why is `static if` different here?

--

https://issues.dlang.org/show_bug.cgi?id=7386

Iain Buclaw <ibuclaw@gdcproject.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P1                          |P3

--

https://issues.dlang.org/show_bug.cgi?id=7386

--- Comment #6 from dlangBugzillaToGithub <robert.schadek@posteo.de> ---
THIS ISSUE HAS BEEN MOVED TO GITHUB

https://github.com/dlang/dmd/issues/18407

DO NOT COMMENT HERE ANYMORE, NOBODY WILL SEE IT, THIS ISSUE HAS BEEN MOVED TO GITHUB

--