I always code constants on the left, to catch just the typo you made in your example.
It gets to be a religious argument. The two sides are:
1) It catches a common typo that is hard for the eye to notice and is hard to debug.
2) It looks ugly and any decent compiler will issue a warning if it sees an assignment in an if conditional.
I think that the second side has the compelling argument, but only if the compiler that is used cooperates. Which all compilers I know of do if you set the options correctly.
Compiling with full warnings on and then getting rid of anything that generates a warning is a great way of catching obscure bugs, even if not every warning is caused by a bug.
-- sidney
