emplace_back

#include <iostream>
#include <vector>

class Noisy
{
public:
    Noisy() : i_{0}
    {
        std::cout << "Noisy default ctor\n";
        count++;
    }
    explicit Noisy (int i) : i_{i}
    {
        std::cout << "Noisy{" << i << "} ctor\n";
        count++;
    }
    Noisy (Noisy const &o) : i_{o.i_}
    {
        std::cout << "Noisy copy ctor " << i_ << "\n";
        count++;
    }
    Noisy& operator= (Noisy const &o)
    {
        if (this == &o)
            std::cout << "Noisy self-(copy assignment) " << i_ << "\n";
        else
        {
            i_ = o.i_;
            std::cout << "Noisy copy assignment " << i_ << "\n";
        }
        return *this;
    }
    Noisy (Noisy&& o) : i_{o.i_}
    {
        o.i_ = -1;
        std::cout << "Noisy move ctor" << i_ << "\n";
    }
    Noisy& operator= (Noisy&& o)
    {
        if (this == &o)
            std::cout << "Noisy self-(move assignment) " << i_ << "\n";
        else
        {
            i_ = o.i_;
            o.i_ = -1;
            std::cout << "Noisy move assignment " << i_ << "\n";
        }
        return *this;
    }
    ~Noisy()
    {
        std::cout << "Noisy dtor " << i_ << "\n";
        count--;
    }
    static void report()
    {
        std::cout << count << " instance(s).\n";
    }
private:
    int i_;
    static int count;
};

int Noisy::count = 0;


int main()
{
    std::vector<Noisy> vec;
    vec.reserve (1000);
    Noisy n1(1);
    vec.emplace_back(n1);
    Noisy n2(2);
    vec.push_back(n2);

    vec.emplace_back(Noisy(3));
    vec.push_back (Noisy (4));
    vec.emplace_back (5);
}