Why “not all control paths return a value” is warning and not an error?

Question

I was trying to answer this question. As suggested by the accepted answer, the problem with that code is that not all control paths are returning a value. I tried this code

Answer 1

here is another reason it isn't an error

the following will give you the same warning since the compiler expects you to return something from the catch block even though you're throwing there

int foo(){
   try{
      return bar(0);
   } catch(std::exception& ex){
      //do cleanup
      throw ex;
   }
}

int bar(unsigned int i){
   if(i == 0){
      throw std::string("Value must be greater than 0");
   } else{
      return 0;
   }
}