extensions enabled by this mode are experimental and may be removed in
future releases of GCC.
+std=c1x
+C ObjC
+Conform to the ISO 201X C standard draft (experimental and incomplete support)
+
std=c89
C ObjC
Conform to the ISO 1990 C standard
standard, dubbed C++0x. Note that the extensions enabled by this mode
are experimental and may be removed in future releases of GCC.
+std=gnu1x
+C ObjC
+Conform to the ISO 201X C standard draft with GNU extensions (experimental and incomplete support)
+
std=gnu89
C ObjC
Conform to the ISO 1990 C standard with GNU extensions