/in/foo.cc: In function 'int main()':
/in/foo.cc:24:8: warning: unused variable 'b' [-Wunused-variable]
   char b;
        ^
/in/foo.cc:41:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int i = 0; i < repo.size(); i++)
                    ~~^~~~~~~~~~~~~
/in/foo.cc:54:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int i = 0; i < repo.size(); i++)
                    ~~^~~~~~~~~~~~~