#include <vector>

void for_vector(){
        //std::vector<int> v;
        std::vector<double> v;
        v.push_back (1.5);
        v.push_back (2);
        v.push_back (-0.90);
        cout<<"v[1],v[2]="<<v[1]<<" "<<v[2]<<" &v[2]="<<&v[2]<<endl;
        cout<<"v.size()= "<<v.size()<<endl;

        v.resize(8);
        cout<<"v.size()= "<<v.size()<<endl;
        //for (int& x: v) {
        cout<<"----using for(int& x:v)-----"<<endl;
        for (double& x: v) {
                cout << &x << "  "<<x<<endl;
        }
        cout<<"----using for(auto x:v)-----"<<endl;
        for (auto x: v) {
                cout << x << endl;
        }
        return;
}


---------------------------------
v[1],v[2]=2 -0.9 &v[2]=0x1708640
v.size()= 3
v.size()= 8
----using for(int& x:v)-----
0x1635150  1.5
0x1635158  2
0x1635160  -0.9
0x1635168  0
0x1635170  0
0x1635178  0
0x1635180  0
0x1635188  0
----using for(auto x:v)-----
1.5
2
-0.9
0
0
0
0
0
[kondo@lxplus748]~/C++%


==================================================

#include <vector>

void for_vector(){
        std::vector<int> v;
        v.push_back (1);
        v.push_back (2);
        v.push_back (3);
        for (int& x: v) {
                cout << x << endl;
        }
        cout<<"----using auto-----"<<endl;
        for (auto x: v) {
                cout << x << endl;
        }
        return;
}

=====================================================

Processing for_vector.C...
1
2
3
----using auto-----
1
2
3