/in/foo.cc: In function 'bool cmp1(student, student)':
/in/foo.cc:23:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'bool cmp2(student, student)':
/in/foo.cc:67:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^