auto_recover: A class to that will restore the value of a variable on scope exit

auto_recover.cpp

#include <iostream>

// ---------------------------------------------
template<typename T>
class auto_recover_t
{
  T& _ref;
  T _value;

public:
  auto_recover_t(T& ref):
    _ref(ref), _value(ref)
  {
  }

  ~auto_recover_t()
  {
    _ref = _value;
  }
};

template<typename T>
auto auto_recover(T& ref) -> auto_recover_t<T>
{
  return {ref};
}
// ---------------------------------------------

int status = 5;

void foo()
{
  const auto recover = auto_recover(status);
  status = 3;
  std::cout << "status in foo: " << status << std::endl;
}

int main()
{
  foo();
  std::cout << "status after returning from foo: " << status << std::endl;
}