gistfile1.txt

#include <vector>
#include <iostream>

class Foo
{
public:
  std::vector<int> m_value;

  Foo() : m_value(10) {}

  std::vector<int> get_value() { return std::move(m_value); }
  std::vector<int>&& move_value() { return std::move(m_value); }
};

int main()
{
  Foo foo;
  std::vector<int> value = foo.get_value();

  Foo foo2;
  foo2.move_value().resize(5); // Bad
  std::vector<int> value2 = foo2.move_value();

  std::cout << value.size() << std::endl;
  std::cout << value2.size() << std::endl;
}