signedness fix

9 jobs for cgg in 5 minutes and 10 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #81363
VS2015
VS2015-32-bit

00:01:17

passed #81362
VS2015
VS2015-64-bit

00:01:31

passed #81361
VS2017
VS2017-32-bit

00:01:26

passed #81360
VS2015
VS2017-64-bit

00:01:34

passed #81357
Linux
clang-c++11

00:03:30

passed #81359
Linux
cppcheck

00:04:44

passed #81364
Linux
doc

00:00:26

passed #81356
Linux
gcc-c++11

00:01:44

passed #81358
Apple
macos-c++11

00:02:34