fix more warnings

7 jobs for master in 3 minutes and 39 seconds
Status Job ID Name Coverage
  Test
passed #13991
Linux
clang-c++11

00:02:25

passed #13993
Linux
clang-c++98

00:01:39

passed #13996
Linux
cppcheck

00:01:46

passed #13990
Linux
gcc-c++11

00:03:38

passed #13992
Linux
gcc-c++98

00:02:33

passed #13994
Apple
macos-c++11

00:02:28

passed #13995
Apple
macos-c++98

00:02:19