[Bug c/44677] Warn for variables incremented but not used (+=, ++)

[vincent-gcc at vinc17 dot net via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44677

--- Comment #28 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> ---
It seems that to get -Wunused-but-set-parameter=3 implicitly, one needs -Wextra
(contrary to -Wunused-but-set-variable=3). So the condition

  -Wunused or -Wall or -Wunused -Wextra or -Wall -Wextra

(which includes the -Wunused alone) seems to be valid only for the
unused-but-set-variable case.