C++ Move

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How to use C++ move?

Just like this:

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#include <iostream>
#include <string>
#include <vector>

void fun(std::string& str)
{
    std::cout << "l-value reference, str=" << str << std::endl;
    std::string temp_str(std::move(str));
    std::cout << "temp_str = move(str), now str=" << str << std::endl;
    std::cout << "temp_str=" << temp_str << std::endl;
}

void fun(std::string&& str)
{
    std::cout << "get r-value reference, build a lvalue str" << std::endl;
    std::cout << "now str=" << str << std::endl;
    std::string temp_str(std::move(str));
    std::cout << "temp_str = move(str), now str=" << str << std::endl;
    std::cout << "temp_str=" << temp_str << std::endl;
}

void array_move()
{
    std::cout << "array move test" << std::endl;
    std::vector<char> array = {'h', '2'};
    std::vector<std::vector<char>> array_vector;
    array_vector.push_back(std::move(array));
    std::cout << "after move, the size of array :" << array.size() << std::endl;
}

int main()
{
    std::string str = "hello,world";
    fun(str);
    std::cout << "after move main: str=" << str << std::endl;
    fun("good");
    array_move();
    return 0;
}