#ifdef vs #if for feature checks

[Norbert Thiebaud]

On Tue, Mar 19, 2013 at 10:25 AM, Christian Lohmaier
<lohmaier+libreoffice at googlemail.com> wrote:
> Hi Tor, *,
>
> On Tue, Mar 19, 2013 at 6:51 AM, Tor Lillqvist <tml at iki.fi> wrote:
>>> otoh, #pragma once is supported by all the compiler we use isn't it ?
>>
>> Excellent! Let's do that, unless somebody comes up with a
>> counter-argument in a week or so.
>
> This doesn't help when the same file is used from two different
> locations, let's say from solver and the module (should not happen,
> but...)

If that was possible, wouldn't that be a bug to be fixed ? (and it is
becoming moot as we move away from delivering headers)

Norbert