bool different in C and C++?

[Berthold Stoeger]

Hi Stefan,

On Sonntag, 19. November 2017 23:07:43 CET Stefan Fuchs wrote:
> Am 18.11.2017 um 19:40 schrieb Berthold Stoeger:
> >> [...]
> >> In fact, even when you can depend on a modern compiler, it's usually
> >> best to restrict "bool" use entirely to just function return values
> >> and very local use.
> > 
> > I figure pref.h counts as such a local use, because it is purely an
> > application-internal thing? Or would you prefer going the short (or char?)
> > route?
> > 
> > bool certainly has the advantage of correctly expressing intent in this
> > case. There are short members in pref.h which actually do represent
> > integer values.
> May I ask you s.th. mainly to learn s.th.:
> I also once added a feature with an additional prefs option where I
> would have preferred the new variable to be a bool. The variable is this
> one here:
> https://github.com/Subsurface-divelog/subsurface/blob/master/core/units.h#L2
> 66
> 
> Using bool there failed with a compiler error. Why was/am I not able to
> use bool there but in prefs.h one can use bool?
> I guess I'm missing s.th. very obvious?
> BTW: I also read the comment in prefs.h about bool at this time and was
> even more confused then ;-)

Hard to say without knowing the error. I believe in C you have to #include 
<stdbool.h> to get bool, true and false defined. History. :)

Berthold