Op woensdag 13-08-2008 om 01:27 uur [tijdzone -0700], schreef leledumbo: > > Sometimes we forgot whether a function argument is passed by reference > or by > value. What if the result is actually important? For instance, > consider the > following (WARNING: True story):
That's not so strange story. I think this is one of the (if not the) most common mistakes of beginning programmers. And -as always- sometimes the most experienced also make this mistake. And there's no way the compiler can detect this. Because this could be intentional. If you'll give a warning on such a construct, I think about 50% of the procedures would gresult in such a warning... And the rules are simple: (for the beginners) procedure Align(Addr: Pointer; Alignment: PtrUInt); -> This procedure can't change any of it's parameters procedure Align(const Addr: Pointer; Alignment: PtrUInt); -> This procedure can't change any of it's parameters, and Addr can't be changed inside the procedure also. procedure Align(var Addr: Pointer; Alignment: PtrUInt); -> This procedure can change Addr If you really need those warnings, you could learn yourself to always use 'const', 'var' or 'out'. And never without any of these words. Joost _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
