데이터 압축 해제를 위해 C에서 사용자 정의 입력/출력 스트림을 구현하는 방법은 무엇입니까?

<code class="cpp">class decompressbuf : public std::streambuf {
    std::streambuf* sbuf_;
    char*           buffer_;
public:
    decompressbuf(std::streambuf* sbuf)
        : sbuf_(sbuf), buffer_(new char[1024]) {}
    ~decompressbuf() { delete[] this->buffer_; }
    int underflow() {
        if (this->gptr() == this->egptr()) {
            // Decompress data into buffer_, obtaining its own input from
            // this->sbuf_; if necessary resize buffer
            // the next statement assumes &quot;size&quot; characters were produced (if
            // no more characters are available, size == 0.
            this->setg(this->buffer_, this->buffer_, this->buffer_ + size);
        }
        return this->gptr() == this->egptr()
             ? std::char_traits<char>::eof()
             : std::char_traits<char>::to_int_type(*this->gptr());
    }
};</code>

<code class="cpp">std::ifstream fin("some.file");
decompressbuf   sbuf(fin.rdbuf());
std::istream  in(&sbuf);</code>