如何为一次只写一位的程序编写测试程序

我正试图为下面的程序编写一个测试程序，看看它是否正常工作，但是，我不确定我是否正确地实现了flush（），由于某种原因，我没有得到任何输出。有人能建议测试这个类的代码，看看我是否正确地实现了flush和writeBit吗？

#ifndef BITOUTPUTSTREAM_HPP
#define BITOUTPUTSTREAM_HPP
#include <iostream>
class BitOutputStream {
private: 
  char buf;             // one byte buffer of bits
  int nbits;            // how many bits have been written to buf
  std::ostream& out;    // reference to the output stream to use
public:
  /* Initialize a BitOutputStream that will 
   * use the given ostream for output. 
   * */
  BitOutputStream(std::ostream& os) : out(os) {
    buf = nbits = 0;    // clear buffer and bit counter
  }
  /* Send the buffer to the output, and clear it */
  void flush() {
  out.put(buf);
  // EDIT: removed flush(); to stop the infinite recursion
  buf = nbits = 0;
  }

  /* Write the least sig bit of arg into buffer */
  int writeBit(int i) {
  // If bit buffer is full, flush it.
  if (nbits == 8) 
    flush();
// Write the least significant bit of i into 
// the buffer at the current index.
// buf = buf << 1;  this is another option I was considering
// buf |= 1 & i;    but decided to go with the one below
  int lb = i & 1;      // extract the lowest bit
  buf |= lb << nbits;  // shift it nbits and put in in buf
  // increment index
  nbits++;
  return nbits;
  }
};
#endif // BITOUTPUTSTREAM_HPP

作为一名测试人员，我写的是：

#include "BitOutputStream.hpp"
#include <iostream>
int main(int argc, char* argv[])
{
  BitOutputStream bos(std::cout);  // channel output to stdout
  bos.writeBit(1);
  // Edit: added lines below
  bos.writeBit(0);
  bos.writeBit(0);
  bos.writeBit(0);
  bos.writeBit(0);
  bos.writeBit(0);
  bos.writeBit(0);
  bos.writeBit(1);
  // now prints an 'A' ;)
  return 0;
}

我知道这是错误的，因为我没有得到任何输出，也没有办法查看实现是否正确。我感谢你能提供的任何意见。

我用以下代码编译了代码：g++-std=c++11 main.cpp BioOutputStream.hpp BitInputStream.cpp并使用以下内容运行：./a.输出