foo.cc: In function ‘bool leap(int)’:
foo.cc:4:18: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
    4 |         if(x%4==0&&x%100!=0||x%400==0)return true;
      |            ~~~~~~^~~~~~~~~~
foo.cc: In function ‘bool m1(int, int)’:
foo.cc:10:26: warning: pointer to a function used in arithmetic [-Wpointer-arith]
   10 |         else if(m==2)d=28+leap;
      |                        ~~^~~~~
foo.cc:10:26: error: invalid conversion from ‘bool (*)(int)’ to ‘int’ [-fpermissive]
   10 |         else if(m==2)d=28+leap;
      |                        ~~^~~~~
      |                          |
      |                          bool (*)(int)