关于#c++#的问题

Question

#include <iostream>
using namespace std;

class temp
{
private:
    char *a;
public:
    temp(char c, char b) 
    { 
        a = new char[2];
        
        a[0] = c;
        a[1] = b; 
        cout << "3" << endl;
    }
    temp(temp &t):a(t.a)
    {
        a = new char[2];
        cout << "2" << endl;
    }

    temp(temp &&t):a(t.a)
    {
        t.a = NULL;
        cout << "1" << endl;
    }
    void show(void)
    {
        printf("%d", a[0]);
    }

    ~temp() { cout << "析构" << endl; delete[] a; }
};

static temp get(void)
{
    temp d(3, 4);
    cout << "666" << endl;
    return d;
}

int main(void)
{
    temp c(1, 2), b = move(c);
    c.show();
    //temp d = get();
    
    system("pause");
    return 0;
}

上面构造函数不是开了空间吗？为什么会指向NULL？

Answer 1

b = move(c); 这个move是啥？