cppSTLEmplaceVsInsert

#include <iostream>
#include <memory>
#include <array>
#include <vector>
#include <forward_list>
#include <list>
#include <algorithm>
#include <functional>

namespace itstep
{
    template <typename InIter, typename Func>
    void for_each(InIter begin, InIter end, Func func)
    {
        for (; begin != end; ++begin)
        {
            func(*begin);
        }
    }

    template <typename T>
    void print(const T& elem, char delimeter = '\0')
    {
        std::cout << elem;
        if (delimeter)
        {
            std::cout << delimeter;
        }
    }

    template <typename T>
    void mul2(T& elem)
    {
        elem *= 2;
    }

}

class Item
{
public:
    Item() { std::cout << "Item default constructed " << this << '\n'; }
    Item(const Item& it) { std::cout << "Item copy constructed " << this << " from " << &it << '\n'; }
    Item(Item&& it) { std::cout << "Item move constructed " << this << " from " << &it << '\n'; }
    Item& operator=(const Item& it) { std::cout << "Item copy assigned " << this << " from " << &it << '\n'; return *this; }
    Item& operator=(Item&& it) { std::cout << "Item move assigned " << this << " from " << &it << '\n'; return *this; }
    ~Item() { std::cout << "Item destructed " << this << '\n'; }
    friend std::ostream& operator<<(std::ostream& out, const Item& item)
    {
        return out << "Item # " << &item;
    }
};



int main()
{
    std::vector<int> arr{1,2,3,4,5,6,7,8,9,10};
    //arr.reserve(150);
    //std::cout << "Original size = " << arr.size() << " capacity = " << arr.capacity() << '\n';

    //for (int i{ 0 }; i < 64; ++i)
    //{
    //  arr.push_back(i);
    //  std::cout << "size = " << arr.size() << " capacity = " << arr.capacity() << '\n';
    //}
    //
    ////arr.shrink_to_fit();
    //arr.resize(32);
    //std::cout << "Shrinked size = " << arr.size() << " capacity = " << arr.capacity() << '\n';
    //arr.reserve(16);
    //std::cout << "Post reserve 16 size = " << arr.size() << " capacity = " << arr.capacity() << '\n';

    //std::copy(arr.begin(), arr.end(), std::ostream_iterator<int>(std::cout, " "));
    //std::cout << '\n';

    //arr.push_back(11);

    //std::copy(arr.begin(), arr.end(), std::ostream_iterator<int>(std::cout, " "));
    //std::cout << '\n';

    //arr.pop_back();
    //std::copy(arr.begin(), arr.end(), std::ostream_iterator<int>(std::cout, " "));
    //std::cout << '\n';

    //std::list<int> newVal{ 42,43,44,45 };

    //arr.insert(arr.begin(), newVal.begin(), newVal.end());
    //std::copy(arr.begin(), arr.end(), std::ostream_iterator<int>(std::cout, " "));
    //std::cout << '\n';

    ////arr.erase(arr.begin(), arr.end());
    ////arr.clear();
    //*arr.begin() = 444;

    //std::copy(arr.begin(), arr.end(), std::ostream_iterator<int>(std::cout, " "));
    //std::cout << '\n';

    Item it;
    std::cout << it << '\n';

    std::vector<Item> items;
    //items.reserve(4);
    items.resize(4);
    std::cout << "Original size = " << items.size() << " capacity = " << items.capacity() << '\n';

    items.insert(items.begin(), it);
    std::copy(items.begin(), items.end(), std::ostream_iterator<Item>(std::cout, " "));
    std::cout << '\n';

    return 0;
}