// single-bit state and operations
//
// #ifndef B1_H_
// #define B1_H_

class B1
{
 private: int b;

 public: B1(); void print(const char msg[]) const;

  void X(); int M(); // NOT, measure

};

// #endif // B1_H_
// single-bit state and operations
//
#include <iostream>
// #include "B1.h"
using namespace std;

B1::B1() { b = 0; }

void B1::print(const char msg[]) const { cout << msg << ": " << b << endl; }

void B1::X() { b = !b; } // NOT

int B1::M() { return b; } // measure
#include <iostream>
// #include "B1.h"
using namespace std;

int main()
{
  B1 b; b.print("b");
  cout << "m = " << b.M() << endl;
  b.X(); b.print("X");
  cout << "m = " << b.M() << endl;
}