foo.cc: In function 'int main()':
foo.cc:5:5: error: expected ';' before 'printf'
     printf("hello, world\n");
     ^~~~~~
foo.cc:5:29: warning: statement has no effect [-Wunused-value]
     printf("hello, world\n");
                             ^

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。