#include <iostream>
#include <streambuf>
#include <cstdio>

extern "C" {
    int write (int fd, const char* buf, int num);
}

class fdoutbuf : public std::streambuf {
  protected:
    int fd;    // file descriptor
  public:
    // constructor
    fdoutbuf (int _fd) : fd(_fd) {
    }
  protected:
    // write one character
    virtual int_type overflow (int_type c) {
        if (c != EOF) {
            char z = c;
            if (write (fd, &z, 1) != 1) {
                return EOF;
            }
        }
        return c;
    }
    // write multiple characters
    virtual
    std::streamsize xsputn (const char* s,
                            std::streamsize num) {
        return write(fd,s,num);
    }
};

class fdostream : public std::ostream {
  protected:
    fdoutbuf buf;
  public:
    fdostream (int fd) : std::ostream(0), buf(fd) {
        rdbuf(&buf);
    }
};