Why can't the operator be overloaded?

Question

C++ / C#

Can't overload operator if return type is bool
If I create a vector from int, then everything is fine
Error:

the initial value of a non-const parameter reference must be a left-hand value

class Test {
private:
  vector<bool> selfVector;
public:
  Test(vector<bool> &_vector):selfVector(_vector) {}

  bool& operator [] (int index) {
    return selfVector[index];
  }
};

vector<bool> myVector = {true, true };
auto test = Test(myVector);
test[0] = false;

Answer 1

bool& operator [] (int index) {
    return selfVector[index];
  }

should become

std::vector<bool>::reference operator [] (int index) {
    return selfVector[index];
  }

Answer 2

Write with templates

Answer 3

Так значит у вас нет такой таблицы в базе.
Миграцию делали после добавления модели?
python manage.py migrate --run-syncdb