std::copy(std::make_move_iterator(s1.begin()),std::make_move_iterator(s1.end()),std::make_move_iterator(s2.begin()));

并得到这个错误：

error: using xvalue (rvalue reference) as lvalue
        *__result = std::move(*__first);

这让我感到困惑.如果你使用std :: move,会发生同样的事情.似乎GCC内部使用了一个名为std :: __ copy_move_a的函数,它移动而不是复制.是否使用std :: copy或std :: move是否重要？

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

struct Test
{
    typedef std::string::value_type value_type;
    std::string data;

    Test()
    {
    }

    Test(const char* data)
        : data(data)
    {
    }

    ~Test()
    {
    }

    Test(const Test& other)
        : data(other.data)
    {
        std::cout << "Copy constructor.\n";
    }

    Test& operator=(const Test& other)
    {
        data = other.data;
        std::cout << "Copy assignment operator.\n";
        return *this;
    }

    Test(Test&& other)
        : data(std::move(other.data))
    {
        std::cout << "Move constructor.\n";
    }

    decltype(data.begin()) begin()
    {
        return data.begin();
    }

    decltype(data.end()) end()
    {
        return data.end();
    }

    void push_back( std::string::value_type ch )
    {
        data.push_back(ch);
    }
};

int main()
{
    Test s1("test");
    Test s2("four");
    std::copy(std::make_move_iterator(s1.begin()),std::make_move_iterator(s2.begin()));
    std::cout << s2.data;
}