How to set a preceding function parameter to its default in c++?

Question

Apologies if this basic question has already been answered. What would I put inside the brackets of print() so that the first parameter is left to the default value but the following parameters are given new values of 1 and 2? I know I can literally put 0 in there but is there a way for it go to a default?

#include<iostream>

using namespace std;

void printer(int a=0, int b=0, int c=0){
 cout << a << endl;
 cout << b << endl;
 cout << c << endl;
}

int main(){

//leave a=0 and replace both b and c 
printer(/*?*/,1,2);

 return 0;
}

Answer 1

You cannot do that, it's not allowed. Only right most parameters could be omitted.

Answer 2

Default parameter list is right associative. So its not possible to ommit first parameter list.