PVS-Studio warning V502 for MongoDB

string sysInfo() {
  ....
  stringstream ss;
  ....
  ss << (sizeof(char *) == 8) ? " 64bit" : " 32bit";
  ....
}

A very nice sample. 0 or 1 will be printed instead of "32bit"/"64bit".

This suspicious code was found in MongoDB project by PVS-Studio static code analyzer.
Warning message is:
V502 Perhaps the '?:' operator works in a different way than it was expected. The '?:' operator has a lower priority than the '<<' operator. version.cpp 107

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/