https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67668
--- Comment #4 from BENAÏSSA <ka_bena at yahoo dot fr> --- Thank you for your quick and clear reply . Note: I think that using the same symbol operator for doing two different things can be a potential source of blind errors. I confirm that this is only a personnal point of view. A.Benaïssa Le Lundi 21 septembre 2015 15h41, manu at gcc dot gnu.org <gcc-bugzi...@gcc.gnu.org> a écrit : https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67668 Manuel López-Ibáñez <manu at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED CC| |manu at gcc dot gnu.org Resolution|--- |INVALID --- Comment #3 from Manuel López-Ibáñez <manu at gcc dot gnu.org> --- Marc is right: The operator ‘~’ performs complex conjugation when used on a value with a complex type. This is a GNU extension; for values of floating type, you should use the ISO C99 functions conjf, conj and conjl, declared in <complex.h> and also provided as built-in functions by GCC. test.c:3:3: warning: ISO C does not support ‘~’ for complex conjugation [-Wpedantic] ~( 1. + 0.i ) ; ^