Re: alias and __VERSION__ condition doesn't play well
On Wednesday, 19 January 2022 at 04:15:54 UTC, Steven
Schveighoffer wrote:
On 1/18/22 7:19 AM, vit wrote:
On Tuesday, 18 January 2022 at 12:05:38 UTC, Paul Backus wrote:
On Tuesday, 18 January 2022 at 04:42:45 UTC, frame wrote:
At the very top of my module I have this declaration:
```d
static if (__VERSION__ >= 2098)
{
alias Foo = TypeA;
}
else
{
alias Foo = TypeB;
}
```
No problem inside the module itself but this doesn't work
when imported from another module:
Error: undefined identifier `Foo`
Works for me: https://run.dlang.io/is/XZlvQ8
It works until you have cyclic dependencies:
https://run.dlang.io/is/wDDcK5
Has nothing to do with `__VERSION__`:
https://run.dlang.io/is/pa8lDy
That does seem like a bug. And it's LDC specific, dmd seems to
work fine.
-Steve
In dmd is order of module compilation different.
Same problem:
https://run.dlang.io/is/NkySAw
This is not only problem with imports:
```d
class Foo{
Bar.B b;
static if(true)
alias F = int;
}
class Bar{
Foo.F f; //Error: no property `F` for type `onlineapp.Foo`
static if(true)
alias B = int;
}
void main(){}
```
Re: alias and __VERSION__ condition doesn't play well
On 1/18/22 7:19 AM, vit wrote:
On Tuesday, 18 January 2022 at 12:05:38 UTC, Paul Backus wrote:
On Tuesday, 18 January 2022 at 04:42:45 UTC, frame wrote:
At the very top of my module I have this declaration:
```d
static if (__VERSION__ >= 2098)
{
alias Foo = TypeA;
}
else
{
alias Foo = TypeB;
}
```
No problem inside the module itself but this doesn't work when
imported from another module:
Error: undefined identifier `Foo`
Works for me: https://run.dlang.io/is/XZlvQ8
It works until you have cyclic dependencies:
https://run.dlang.io/is/wDDcK5
Has nothing to do with `__VERSION__`:
https://run.dlang.io/is/pa8lDy
That does seem like a bug. And it's LDC specific, dmd seems to work fine.
-Steve
Re: alias and __VERSION__ condition doesn't play well
On Tuesday, 18 January 2022 at 12:05:38 UTC, Paul Backus wrote:
On Tuesday, 18 January 2022 at 04:42:45 UTC, frame wrote:
At the very top of my module I have this declaration:
```d
static if (__VERSION__ >= 2098)
{
alias Foo = TypeA;
}
else
{
alias Foo = TypeB;
}
```
No problem inside the module itself but this doesn't work when
imported from another module:
Error: undefined identifier `Foo`
Works for me: https://run.dlang.io/is/XZlvQ8
It works until you have cyclic dependencies:
https://run.dlang.io/is/wDDcK5
Re: alias and __VERSION__ condition doesn't play well
On Tuesday, 18 January 2022 at 04:42:45 UTC, frame wrote:
At the very top of my module I have this declaration:
```d
static if (__VERSION__ >= 2098)
{
alias Foo = TypeA;
}
else
{
alias Foo = TypeB;
}
```
No problem inside the module itself but this doesn't work when
imported from another module:
Error: undefined identifier `Foo`
Works for me: https://run.dlang.io/is/XZlvQ8
Re: alias and __VERSION__ condition doesn't play well
On Tuesday, 18 January 2022 at 04:42:45 UTC, frame wrote:
At the very top of my module I have this declaration:
```d
static if (__VERSION__ >= 2098)
{
alias Foo = TypeA;
}
else
{
alias Foo = TypeB;
}
```
No problem inside the module itself but this doesn't work when
imported from another module:
Error: undefined identifier `Foo`
While this workaround works:
```d
template getAlias()
{
static if (__VERSION__ >= 2098)
{
alias getAlias = TypeA;
}
else
{
alias getAlias = TypeB;
}
}
alias Foo = getAlias!();
```
Is there a reason for that?
static ifs and mixins need semantic analysis to expand, but when
you import module, the semantic analysis doesn't run yet (depends
on order).
Beter workaround is:
```d
import std.traits : Select;
alias Foo = Select!(__VERSION__ >= 2098, TypeA, TypeB);
```
alias and __VERSION__ condition doesn't play well
At the very top of my module I have this declaration:
```d
static if (__VERSION__ >= 2098)
{
alias Foo = TypeA;
}
else
{
alias Foo = TypeB;
}
```
No problem inside the module itself but this doesn't work when
imported from another module:
Error: undefined identifier `Foo`
While this workaround works:
```d
template getAlias()
{
static if (__VERSION__ >= 2098)
{
alias getAlias = TypeA;
}
else
{
alias getAlias = TypeB;
}
}
alias Foo = getAlias!();
```
Is there a reason for that?
