CMake build failure

[baylesj]

Scanning dependencies of target jsoncpp_test
[ 38%] Building CXX object src/test_lib_json/CMakeFiles/jsoncpp_test.dir/main.cpp.o
/usr/local/src/jsoncpp/src/test_lib_json/main.cpp:128:41: error: implicit conversion changes signedness: 'int' to
'unsigned long' [-Werror,-Wsign-conversion]
auto exponentStartIndex = index + 1 + hasSign;
~ ^~~~~~~
1 error generated.

[BillyDonahue]

The warning isn't wrong. The hasSign on the preceding line should be a size_t.