set_cflags_if_supported(

  -Wextra

  -Wbad-function-cast

  -Wno-missing-noreturn

  -Wstrict-prototypes

  -Wmissing-prototypes

  -Wmissing-declarations

  -Wpointer-arith

  #-Wshadow will fail with GCC-8

  ${OPTIONAL_CFLAGS}

  ## other flags to try:

  #-Wunsafe-loop-optimizations

  #-Wpointer-arith

  #-Wc++-compat

  #-Wc++11-compat

  #-Wwrite-strings

  #-Wzero-as-null-pointer-constant

  #-Wlogical-op

  #-Wvector-optimization-performance

  )

-Wbad-function-cast

-Wstrict-prototypes

-Wmissing-prototypes

Warnings:

cc1plus: warning: command line option '-Wbad-function-cast' is valid for C/ObjC but not for C++

cc1plus: warning: command line option '-Wstrict-prototypes' is valid for C/ObjC but not for C++

cc1plus: warning: command line option '-Wmissing-prototypes' is valid for C/ObjC but not for C++