Hi, I am a programmer of C files. I would like to know about gcc compile option "-std=" of GCC 3.4.3 I have 4 files , a.c, b.c, x.c, y.c. which will be compiled and linked to 1 binary file. If I compile a.c and b.c without option "-std=" and compile x.c and y.c with option "-std=c99", will the binary file have any touble in execution ?