------- Comment #10 from bangerth at gmail dot com 2010-02-21 01:25 ------- (In reply to comment #7) > (In reply to comment #3) > > As another data-point, > > > > if ( (a=10) ) ; > > > > also doesn't warn. I'm not sure what the standard says on that, but other > > contemporary compilers do give the an "assignment used as truth value" > > warning > > for the example above. > > > > How do other compilers deal with false positives? That is, how can a > programmer > specify that they really want to do an assignment? > > We could use a cast to bool.
I think at least in C++ the warning is useful. Conditions in if(...) statements have type bool, and things like if (a=10) use the implicit conversion from int to bool. If a programmer wants to avoid the warning, one can always be explicit and write if ( (a=10) != 0) W. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25733
