Am 02.07.2017 um 19:51 schrieb Martok: > Booleans are not enums in Delphi (not even ordinals),
They are: http://docwiki.embarcadero.com/Libraries/XE5/en/System.Boolean > but their own little > thing. "if boolean_expr" is always a jz/jnz, no matter what. Yes. This is an optimization which is invalid as well if I follow your argumentation. Boolean(3)<>true. > They are defined as > 0=FALSE and "everything else"=TRUE No, see link above. > > However: > > var > b : boolean; > begin > b:=boolean(3); > if b = True then > writeln(true) > else if b = False then > writeln(false) > else > writeln(ord(b)); > end. > > That writes 3, Yes. What I wanted to point out: also delphi does optimizations on enums which fails if one feeds invalid values. > which is why your should never compare on the boolean lexicals. > Some Winapi functions returning longbool rely on that. No, longbool is something different (even bytebool is). > > Wait, that was a trick question, wasn't it? In the sense to point out that also delphi assumes enumeration variables contain always valid values. _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
