Am 24.09.2014 um 02:59 schrieb Роман:
> As we all know, C preprocessor allows function-like macros, including ones
> with empty expansion.
> They can be very convenient for things that you'll want to disable depending
> on conditional defines,
> such as logging or assertions.
>
> #ifdef DEBUG
> #define dprf(...) print_debug_message(__VA_ARGS__)
> #else
> #define dprf(...)
> #endif
>
> I have a temptation to use this in FPC too. Here's a trick:
>
> {$macro on}
> {$ifdef DEBUG}
> {$define Log := ActualLog}
> {$else}
> {$define Log := ;//}
> {$endif}
>
> if A then
> Log('will work until followed by ELSE at all or any statements on the same
> line (because of ; and
> //, respectively).');
> if B then
> Log('And should not be carried over to the next line, of course!');
>
> Because constant {$ifdef DEBUG} ActualLog(...); {$endif} are rather
> cumbersome.
>
> This is by design? Can I rely on this behavior in the future? ._.
As far as the example above is concerned, yes. Macros just do a textual
replacement.
_______________________________________________
fpc-pascal maillist - fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
