C++ Primer P8-3

#include 
#include 
#include 
using namespace std;
string & Toupper(string & a);
int main() {
    cout << "enter a string (q to quit): " << endl;
    string inputs;
    string & cinputs = inputs;
    getline(cin, inputs);
    while (inputs != "q"){
        cout << Toupper(cinputs) << endl;
        cout << "next string: " << endl;
        getline(cin, inputs);
    }
    cout << "bye!";

    return 0;
}

string & Toupper(string & a){
    //a = toupper(a);
    int i = 0;
    while(a[i]){
        a[i] = toupper(a[i]);
        i++;
    }
    return a;
}