From: Chris Uzdavinis <chris@uzdavinis.com>
Rene Rivera <grafik.list@redshift-software.com> writes:
It's possible without macros for some compilers using careful template instaciations.
For example the very simple logger I wrote uses syntax like so (and yes I prefer printf formatting :-)...
log<RevisionLog>::trace( "RevisionControl::commit_; wait for ticket #%d",ticket);
Because the formatting is done by the trace call, and the trace call is empty (and inlined) when the log is disabled, no formatting takes place. Something similar can be done regardless of what the formatting object is by having a specialization that does nothing.
That does not eliminiate any overhead that may exist due to evaluating the function arguments prior to making the call, nor any potential side effects of those expressions.
Personally, having debugging log statements completely disappear from the source code in a release build is more comforting, even if it involves a macro.
There are also plenty of times in which you want logging available in release builds but you want minimal overhead when it is disabled. A macro helps there, too, by moving the evaluation of the argument list into the body of a conditional statement. -- Rob Stewart stewart@sig.com Software Engineer http://www.sig.com Susquehanna International Group, LLP using std::disclaimer;