C++ move semantics in a nutshell

move.cpp

#include <iostream>
#include <string>

using namespace std;

class A
{
public:
  A(const string & a) : value(a)
  {
    cout << "A(const string & a)" << endl;

  }

  A(string && a) : value(move(a))
  {
    cout << "A(string && a)" << endl;
  }

  string value;
};

string get_string()
{
  return "value";
}

int main(int argc, const char ** argv)
{
  {
    string value("value");
    cout << "A a(value):" <<endl;
    A a(value);
    cout << a.value << endl << endl;
  }
  {
    cout << "A a(get_string()):" <<endl;
    A a(get_string());
    cout << a.value << endl << endl;
  }
  {
    string value("value");
    cout << "A a(move(value)):" <<endl;
    A a(move(value));
    cout << a.value << endl << endl;
  }
  return 0;
}