/in/foo.cc: In function 'bool compare3(num, num)':
/in/foo.cc:77:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for(int i=a.len;i>=1;i--)
     ^~~
/in/foo.cc:79:9: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
         return 1;
         ^~~~~~
/in/foo.cc: In function 'num operator*(num, num)':
/in/foo.cc:51:26: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
             t.data[t.len]=y;
             ~~~~~~~~~~~~~^~