Detecta palindromos (C++)

#include <iostream>

using namespace std;

bool palindromo(string &s);

int main()
{
    string s="racecar";
    while(cin>>s){
        if(s=="end")
            break;
        if(palindromo(s))
            cout<<"Es palindromo";
        else cout<<"No es";
        cout<<"\n"; //endl
    }
    cout<<"He salido y ahora termino\n";
}

bool palindromo(string &s){
    for(int i=0;i<s.length()/2;i++){
        if(s[i]!=s[s.length()-1-i])
            return false;
    }
    return true;
}