Function call evaluation order

#include <iostream>


typedef void (*func_t)(int x);

void func(int x){
   std::cout << "evaluate function    ";
}

func_t f(){
   return &func;
}


int x(){
   std::cout << "evaluate arg    ";
   return 5;
}


int main(){
   while(true){
      f()(x());
      std::cout << std::endl;
   }
}