Thank you John! Do you mean _DEBUG is not defined and used by gcc itself on Linux platform and it may be used in application code (especially the ones from Microsoft Windows platform)? regards, George --- John Love-Jensen <eljay@xxxxxxxxx> wrote: > Hi George, > > The _DEBUG define is (as far as I am aware) a > Microsoft-ism convention. > Some people have taken that convention to heart, and > rely upon it in their > own environments -- even non-Microsoft environments. > > For debug builds, the _DEBUG is defined. Caution: > in C++, _DEBUG is a > reserved identifier, use at your own peril. > (Microsoft legitimately uses it > in their compiler, since those kind of identifiers > are reserved for the > compiler vendor to use as they see fit.) > > For non-debug builds (release builds), the NDEBUG is > defined. Note: NDEBUG > has a long history in C. Look at the "assert.h" > header. I believe NDEBUG > is used on every platform that supports C/C++. If > an "NDEBUG" symbol were > to be introduced today, it would be _NDEBUG, but > because of its provenance, > it is NDEBUG. > > I recommend using the presence or absence of NDEBUG > as the trigger for code > that is release (#ifdef NDEBUG) or debug (#ifndef > NDEBUG). Even thought I > have a bit of distaste for "#ifndef NDEBUG" because > of the double-negative > makes my tiny little brain hurt. > > HTH, > --Eljay > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
