http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47605
Summary: Document that C_Bool might be the wrong constant for C Booleans Product: gcc Version: 4.6.0 Status: UNCONFIRMED Keywords: documentation Severity: normal Priority: P3 Component: fortran AssignedTo: unassig...@gcc.gnu.org ReportedBy: bur...@gcc.gnu.org James pointed out the following at http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/3c2784c55d402ced c_bool is typically one byte wide, and c_int 4. That means: Most C programs - except of those few which explicitly use _Bool, use a 4 byte and not a 1 byte Boolean variables. I think one should put a warning into the manual - either in the C Binding part [1] or in the section about the ISO C Binding constants [2], or in both. [1] http://gcc.gnu.org/onlinedocs/gfortran/Intrinsic-Types.html [2]http://gcc.gnu.org/onlinedocs/gfortran/ISO_005fC_005fBINDING.html