Using c++11 range-base for loop, C++ (gcc)

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//Title of this code
//
// range-based for
//

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <iterator>

using namespace std;

template<class T>
    ostream& operator<<(ostream& cout, const vector<T>& v){
    for(T i : v){
        cout << i << " ";
    }
    return cout;
}

void msgToUser(){
    string userName("", 125);
    cout << "User's name:\t";
    getline(cin, userName, '\n');
    cout << userName << endl;
    cout << "Good day " << userName << endl;
};

template<class T>
class InitData{
    private:
        T val;
        //T res;
    
    public:
        InitData(){};
        InitData(const T& init): val(init){};
        ~InitData(){};
    
        T operator()(){
            return val++;
            
        };
};

int main(){
    msgToUser();
    
    double d{1.5};
    cout << "d = " << d << endl;
    
    vector<double>v1{1,2,3,4.5,5.25};
    vector<int>iv1{1,2,6,4,2,8,9,10};
    vector<double>v2 = {5,10,20,40,80};
    
    vector<char>UC(26);
    vector<char>LC(26);    
    
    cout << endl;
    cout << "v1 size = " << v1.size() << endl;
    cout << "v1 content:\t" << v1 << endl;
    
    cout << "\niv1 size = " << iv1.size() << endl;
    cout << "iv1 contents:\t" << iv1 << endl;
    
    cout << "\nv2 contents:\t" << v2 << endl;
    
    auto d1 = 2.25;
    auto lc = 'a';
    auto uc = 'A';
    
    auto Int = {4095, 8025, 16};    
    int IntSize = sizeof(Int)/sizeof(int);
    vector<int>iv2(Int);
    cout << "iv2:\t" << iv2 << endl;
    
    vector<double>v3(10);
    InitData<double>gen(1.25);
    generate(v3.begin(), v3.end(), gen);
    cout << "v3:\t" << v3 << endl;
    
    vector<int>v4(10);
    InitData<int>iGen(1);
    generate(v4.begin(), v4.end(), iGen);
    cout << "v4:\t" << v4 << endl;   
 
    
    InitData<char>ucgen(uc);
    InitData<char>lcgen(lc);
    generate(UC.begin(), UC.end(), ucgen);
    generate(LC.begin(), LC.end(), lcgen);
    
    cout << "Upper case set:\t" << UC << endl;
    cout << "Lower case set:\t" << LC << endl;
        
    return 0;
}

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Compilation time: 0.79 sec, absolute running time: 0.14 sec, cpu time: 0 sec, memory peak: 3 Mb, absolute service time: 0.94 sec