/in/foo.cc: In function 'bool IDcmp(Player, Player)':
/in/foo.cc:14:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < p1.ID.length(); i++)
                     ~~^~~~~~~~~~~~~~~~
/in/foo.cc: In function 'bool tiecmp(Player, Player)':
/in/foo.cc:29:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int i = 0; i < p1.tiecount.length(); i++)
                    ~~^~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'bool IDcmp(Player, Player)':
/in/foo.cc:21:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^