Add CMAKE_CXX_FLAGS

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

CMakeLists.txt

@@ -44,6 +44,7 @@ set(SLIM_DEFINITIONS ${SLIM_DEFINITIONS} "-DSYSCONFDIR=\"${SYSCONFDIR}\"")
 # Flags
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -g -O2" )
 set(CMAKE_CPP_FLAGS "${CMAKE_CPP_FLAGS} -Wall -g -O2" )
+set(CMAKE_CXX_FLAGS "${CMAKE_CPP_FLAGS} -Wall -g -O2" )
 
 # source 
 set(slim_srcs