foo.cc: In function ‘bool pf(int)’:
foo.cc:7:17: warning: this ‘for’ clause does not guard... [-Wmisleading-indentation]
    7 |                 for(int j=i;j*j<=n;j++)
      |                 ^~~
foo.cc:9:25: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘for’
    9 |                         return 0;
      |                         ^~~~~~