contrib/iostream3/zfstream.h

/*
 * A C++ I/O streams interface to the zlib gz* functions
 *
 * by Ludwig Schwardt <schwardt@sun.ac.za>
 * original version by Kevin Ruland <kevin@rodin.wustl.edu>
 *
 * This version is standard-compliant and compatible with gcc 3.x.
 */

#ifndef ZFSTREAM_H
#define ZFSTREAM_H

#include <istream>  // not iostream, since we don't need cin/cout
#include <ostream>
#include "zlib.h"

/*****************************************************************************/

/**
 *  @brief  Gzipped file stream buffer class.
 *
 *  This class implements basic_filebuf for gzipped files. It doesn't yet support
 *  seeking (allowed by zlib but slow/limited), putback and read/write access
 *  (tricky). Otherwise, it attempts to be a drop-in replacement for the standard
 *  file streambuf.
*/
class gzfilebuf : public std::streambuf
{
public:
  //  Default constructor.
  gzfilebuf();

  //  Destructor.
  virtual
  ~gzfilebuf();

  /**
   *  @brief  Set compression level and strategy on the fly.
   *  @param  comp_level  Compression level (see zlib.h for allowed values)
   *  @param  comp_strategy  Compression strategy (see zlib.h for allowed values)
   *  @return  Z_OK on success, Z_STREAM_ERROR otherwise.
   *
   *  Unfortunately, these parameters cannot be modified separately, as the
   *  previous zfstream version assumed. Since the strategy is seldom changed,
   *  it can default and setcompression(level) then becomes like the old
   *  setcompressionlevel(level).
  */
  int
  setcompression(int comp_level,
                 int comp_strategy = Z_DEFAULT_STRATEGY);

  /**
   *  @brief  Check if file is open.
   *  @return  True if file is open.
  */
  bool
  is_open() const { return (file != NULL); }

  /**
   *  @brief  Open gzipped file.
   *  @param  name  File name.
   *  @param  mode  Open mode flags.
   *  @return  @c this on success, NULL on failure.
  */
  gzfilebuf*
  open(const char* name,
       std::ios_base::openmode mode);

  /**
   *  @brief  Attach to already open gzipped file.
   *  @param  fd  File descriptor.
   *  @param  mode  Open mode flags.
   *  @return  @c this on success, NULL on failure.
  */
  gzfilebuf*
  attach(int fd,
         std::ios_base::openmode mode);

  /**
   *  @brief  Close gzipped file.
   *  @return  @c this on success, NULL on failure.
  */
  gzfilebuf*
  close();

protected:
  /**
   *  @brief  Convert ios open mode int to mode string used by zlib.
   *  @return  True if valid mode flag combination.
  */
  bool
  open_mode(std::ios_base::openmode mode,
            char* c_mode) const;

  /**
   *  @brief  Number of characters available in stream buffer.
   *  @return  Number of characters.
   *
   *  This indicates number of characters in get area of stream buffer.
   *  These characters can be read without accessing the gzipped file.
  */
  virtual std::streamsize
  showmanyc();

  /**
   *  @brief  Fill get area from gzipped file.
   *  @return  First character in get area on success, EOF on error.
   *
   *  This actually reads characters from gzipped file to stream
   *  buffer. Always buffered.
  */
  virtual int_type
  underflow();

  /**
   *  @brief  Write put area to gzipped file.
   *  @param  c  Extra character to add to buffer contents.
   *  @return  Non-EOF on success, EOF on error.
   *
   *  This actually writes characters in stream buffer to
   *  gzipped file. With unbuffered output this is done one
   *  character at a time.
  */
  virtual int_type
  overflow(int_type c = traits_type::eof());

  /**
   *  @brief  Installs external stream buffer.
   *  @param  p  Pointer to char buffer.
   *  @param  n  Size of external buffer.
   *  @return  @c this on success, NULL on failure.
   *
   *  Call setbuf(0,0) to enable unbuffered output.
  */
  virtual std::streambuf*
  setbuf(char_type* p,
         std::streamsize n);

  /**
   *  @brief  Flush stream buffer to file.
   *  @return  0 on success, -1 on error.
   *
   *  This calls underflow(EOF) to do the job.
  */
  virtual int
  sync();

//
// Some future enhancements
//
//  virtual int_type uflow();
//  virtual int_type pbackfail(int_type c = traits_type::eof());
//  virtual pos_type
//  seekoff(off_type off,
//          std::ios_base::seekdir way,
//          std::ios_base::openmode mode = std::ios_base::in|std::ios_base::out);
//  virtual pos_type
//  seekpos(pos_type sp,
//          std::ios_base::openmode mode = std::ios_base::in|std::ios_base::out);

private:
  /**
   *  @brief  Allocate internal buffer.
   *
   *  This function is safe to call multiple times. It will ensure
   *  that a proper internal buffer exists if it is required. If the
   *  buffer already exists or is external, the buffer pointers will be
   *  reset to their original state.
  */
  void
  enable_buffer();

  /**
   *  @brief  Destroy internal buffer.
   *
   *  This function is safe to call multiple times. It will ensure
   *  that the internal buffer is deallocated if it exists. In any
   *  case, it will also reset the buffer pointers.
  */
  void
  disable_buffer();

  /**
   *  Underlying file pointer.
  */
  gzFile file;

  /**
   *  Mode in which file was opened.
  */
  std::ios_base::openmode io_mode;

  /**
   *  @brief  True if this object owns file descriptor.
   *
   *  This makes the class responsible for closing the file
   *  upon destruction.
  */
  bool own_fd;

  /**
   *  @brief  Stream buffer.
   *
   *  For simplicity this remains allocated on the free store for the
   *  entire life span of the gzfilebuf object, unless replaced by setbuf.
  */
  char_type* buffer;

  /**
   *  @brief  Stream buffer size.
   *
   *  Defaults to system default buffer size (typically 8192 bytes).
   *  Modified by setbuf.
  */
  std::streamsize buffer_size;

  /**
   *  @brief  True if this object owns stream buffer.
   *
   *  This makes the class responsible for deleting the buffer
   *  upon destruction.
  */
  bool own_buffer;
};

/*****************************************************************************/

/**
 *  @brief  Gzipped file input stream class.
 *
 *  This class implements ifstream for gzipped files. Seeking and putback
 *  is not supported yet.
*/
class gzifstream : public std::istream
{
public:
  //  Default constructor
  gzifstream();

  /**
   *  @brief  Construct stream on gzipped file to be opened.
   *  @param  name  File name.
   *  @param  mode  Open mode flags (forced to contain ios::in).
  */
  explicit
  gzifstream(const char* name,
             std::ios_base::openmode mode = std::ios_base::in);

  /**
   *  @brief  Construct stream on already open gzipped file.
   *  @param  fd    File descriptor.
   *  @param  mode  Open mode flags (forced to contain ios::in).
  */
  explicit
  gzifstream(int fd,
             std::ios_base::openmode mode = std::ios_base::in);

  /**
   *  Obtain underlying stream buffer.
  */
  gzfilebuf*
  rdbuf() const
  { return const_cast<gzfilebuf*>(&sb); }

  /**
   *  @brief  Check if file is open.
   *  @return  True if file is open.
  */
  bool
  is_open() { return sb.is_open(); }

  /**
   *  @brief  Open gzipped file.
   *  @param  name  File name.
   *  @param  mode  Open mode flags (forced to contain ios::in).
   *
   *  Stream will be in state good() if file opens successfully;
   *  otherwise in state fail(). This differs from the behavior of
   *  ifstream, which never sets the state to good() and therefore
   *  won't allow you to reuse the stream for a second file unless
   *  you manually clear() the state. The choice is a matter of
   *  convenience.
  */
  void
  open(const char* name,
       std::ios_base::openmode mode = std::ios_base::in);

  /**
   *  @brief  Attach to already open gzipped file.
   *  @param  fd  File descriptor.
   *  @param  mode  Open mode flags (forced to contain ios::in).
   *
   *  Stream will be in state good() if attach succeeded; otherwise
   *  in state fail().
  */
  void
  attach(int fd,
         std::ios_base::openmode mode = std::ios_base::in);

  /**
   *  @brief  Close gzipped file.
   *
   *  Stream will be in state fail() if close failed.
  */
  void
  close();

private:
  /**
   *  Underlying stream buffer.
  */
  gzfilebuf sb;
};

/*****************************************************************************/

/**
 *  @brief  Gzipped file output stream class.
 *
 *  This class implements ofstream for gzipped files. Seeking and putback
 *  is not supported yet.
*/
class gzofstream : public std::ostream
{
public:
  //  Default constructor
  gzofstream();

  /**
   *  @brief  Construct stream on gzipped file to be opened.
   *  @param  name  File name.
   *  @param  mode  Open mode flags (forced to contain ios::out).
  */
  explicit
  gzofstream(const char* name,
             std::ios_base::openmode mode = std::ios_base::out);

  /**
   *  @brief  Construct stream on already open gzipped file.
   *  @param  fd    File descriptor.
   *  @param  mode  Open mode flags (forced to contain ios::out).
  */
  explicit
  gzofstream(int fd,
             std::ios_base::openmode mode = std::ios_base::out);

  /**
   *  Obtain underlying stream buffer.
  */
  gzfilebuf*
  rdbuf() const
  { return const_cast<gzfilebuf*>(&sb); }

  /**
   *  @brief  Check if file is open.
   *  @return  True if file is open.
  */
  bool
  is_open() { return sb.is_open(); }

  /**
   *  @brief  Open gzipped file.
   *  @param  name  File name.
   *  @param  mode  Open mode flags (forced to contain ios::out).
   *
   *  Stream will be in state good() if file opens successfully;
   *  otherwise in state fail(). This differs from the behavior of
   *  ofstream, which never sets the state to good() and therefore
   *  won't allow you to reuse the stream for a second file unless
   *  you manually clear() the state. The choice is a matter of
   *  convenience.
  */
  void
  open(const char* name,
       std::ios_base::openmode mode = std::ios_base::out);

  /**
   *  @brief  Attach to already open gzipped file.
   *  @param  fd  File descriptor.
   *  @param  mode  Open mode flags (forced to contain ios::out).
   *
   *  Stream will be in state good() if attach succeeded; otherwise
   *  in state fail().
  */
  void
  attach(int fd,
         std::ios_base::openmode mode = std::ios_base::out);

  /**
   *  @brief  Close gzipped file.
   *
   *  Stream will be in state fail() if close failed.
  */
  void
  close();

private:
  /**
   *  Underlying stream buffer.
  */
  gzfilebuf sb;
};

/*****************************************************************************/

/**
 *  @brief  Gzipped file output stream manipulator class.
 *
 *  This class defines a two-argument manipulator for gzofstream. It is used
 *  as base for the setcompression(int,int) manipulator.
*/
template<typename T1, typename T2>
  class gzomanip2
  {
  public:
    // Allows insertor to peek at internals
    template <typename Ta, typename Tb>
      friend gzofstream&
      operator<<(gzofstream&,
                 const gzomanip2<Ta,Tb>&);

    // Constructor
    gzomanip2(gzofstream& (*f)(gzofstream&, T1, T2),
              T1 v1,
              T2 v2);
  private:
    // Underlying manipulator function
    gzofstream&
    (*func)(gzofstream&, T1, T2);

    // Arguments for manipulator function
    T1 val1;
    T2 val2;
  };

/*****************************************************************************/

// Manipulator function thunks through to stream buffer
inline gzofstream&
setcompression(gzofstream &gzs, int l, int s = Z_DEFAULT_STRATEGY)
{
  (gzs.rdbuf())->setcompression(l, s);
  return gzs;
}

// Manipulator constructor stores arguments
template<typename T1, typename T2>
  inline
  gzomanip2<T1,T2>::gzomanip2(gzofstream &(*f)(gzofstream &, T1, T2),
                              T1 v1,
                              T2 v2)
  : func(f), val1(v1), val2(v2)
  { }

// Insertor applies underlying manipulator function to stream
template<typename T1, typename T2>
  inline gzofstream&
  operator<<(gzofstream& s, const gzomanip2<T1,T2>& m)
  { return (*m.func)(s, m.val1, m.val2); }

// Insert this onto stream to simplify setting of compression level
inline gzomanip2<int,int>
setcompression(int l, int s = Z_DEFAULT_STRATEGY)
{ return gzomanip2<int,int>(&setcompression, l, s); }

#endif // ZFSTREAM_H
Revision:	1096
Committed:	Sat Dec 30 14:40:33 2017 UTC (7 years, 9 months ago) by s10k
Content type:	text/x-chdr
File size:	12240 byte(s)
Log Message:	Added zlib, quazip, basicxmlsyntaxhighlighter, conditionalsemaphore and linenumberdisplay libraries. zlib and quazip are pre-compiled, but you can compile them yourself, just delete the dll files (or equivalent binary files to your OS)
#	Content
1	/*
2	* A C++ I/O streams interface to the zlib gz* functions
3	*
4	* by Ludwig Schwardt <schwardt@sun.ac.za>
5	* original version by Kevin Ruland <kevin@rodin.wustl.edu>
6	*
7	* This version is standard-compliant and compatible with gcc 3.x.
8	*/
9
10	#ifndef ZFSTREAM_H
11	#define ZFSTREAM_H
12
13	#include <istream> // not iostream, since we don't need cin/cout
14	#include <ostream>
15	#include "zlib.h"
16
17	/*****************************************************************************/
18
19	/**
20	* @brief Gzipped file stream buffer class.
21	*
22	* This class implements basic_filebuf for gzipped files. It doesn't yet support
23	* seeking (allowed by zlib but slow/limited), putback and read/write access
24	* (tricky). Otherwise, it attempts to be a drop-in replacement for the standard
25	* file streambuf.
26	*/
27	class gzfilebuf : public std::streambuf
28	{
29	public:
30	// Default constructor.
31	gzfilebuf();
32
33	// Destructor.
34	virtual
35	~gzfilebuf();
36
37	/**
38	* @brief Set compression level and strategy on the fly.
39	* @param comp_level Compression level (see zlib.h for allowed values)
40	* @param comp_strategy Compression strategy (see zlib.h for allowed values)
41	* @return Z_OK on success, Z_STREAM_ERROR otherwise.
42	*
43	* Unfortunately, these parameters cannot be modified separately, as the
44	* previous zfstream version assumed. Since the strategy is seldom changed,
45	* it can default and setcompression(level) then becomes like the old
46	* setcompressionlevel(level).
47	*/
48	int
49	setcompression(int comp_level,
50	int comp_strategy = Z_DEFAULT_STRATEGY);
51
52	/**
53	* @brief Check if file is open.
54	* @return True if file is open.
55	*/
56	bool
57	is_open() const { return (file != NULL); }
58
59	/**
60	* @brief Open gzipped file.
61	* @param name File name.
62	* @param mode Open mode flags.
63	* @return @c this on success, NULL on failure.
64	*/
65	gzfilebuf*
66	open(const char* name,
67	std::ios_base::openmode mode);
68
69	/**
70	* @brief Attach to already open gzipped file.
71	* @param fd File descriptor.
72	* @param mode Open mode flags.
73	* @return @c this on success, NULL on failure.
74	*/
75	gzfilebuf*
76	attach(int fd,
77	std::ios_base::openmode mode);
78
79	/**
80	* @brief Close gzipped file.
81	* @return @c this on success, NULL on failure.
82	*/
83	gzfilebuf*
84	close();
85
86	protected:
87	/**
88	* @brief Convert ios open mode int to mode string used by zlib.
89	* @return True if valid mode flag combination.
90	*/
91	bool
92	open_mode(std::ios_base::openmode mode,
93	char* c_mode) const;
94
95	/**
96	* @brief Number of characters available in stream buffer.
97	* @return Number of characters.
98	*
99	* This indicates number of characters in get area of stream buffer.
100	* These characters can be read without accessing the gzipped file.
101	*/
102	virtual std::streamsize
103	showmanyc();
104
105	/**
106	* @brief Fill get area from gzipped file.
107	* @return First character in get area on success, EOF on error.
108	*
109	* This actually reads characters from gzipped file to stream
110	* buffer. Always buffered.
111	*/
112	virtual int_type
113	underflow();
114
115	/**
116	* @brief Write put area to gzipped file.
117	* @param c Extra character to add to buffer contents.
118	* @return Non-EOF on success, EOF on error.
119	*
120	* This actually writes characters in stream buffer to
121	* gzipped file. With unbuffered output this is done one
122	* character at a time.
123	*/
124	virtual int_type
125	overflow(int_type c = traits_type::eof());
126
127	/**
128	* @brief Installs external stream buffer.
129	* @param p Pointer to char buffer.
130	* @param n Size of external buffer.
131	* @return @c this on success, NULL on failure.
132	*
133	* Call setbuf(0,0) to enable unbuffered output.
134	*/
135	virtual std::streambuf*
136	setbuf(char_type* p,
137	std::streamsize n);
138
139	/**
140	* @brief Flush stream buffer to file.
141	* @return 0 on success, -1 on error.
142	*
143	* This calls underflow(EOF) to do the job.
144	*/
145	virtual int
146	sync();
147
148	//
149	// Some future enhancements
150	//
151	// virtual int_type uflow();
152	// virtual int_type pbackfail(int_type c = traits_type::eof());
153	// virtual pos_type
154	// seekoff(off_type off,
155	// std::ios_base::seekdir way,
156	// std::ios_base::openmode mode = std::ios_base::in\|std::ios_base::out);
157	// virtual pos_type
158	// seekpos(pos_type sp,
159	// std::ios_base::openmode mode = std::ios_base::in\|std::ios_base::out);
160
161	private:
162	/**
163	* @brief Allocate internal buffer.
164	*
165	* This function is safe to call multiple times. It will ensure
166	* that a proper internal buffer exists if it is required. If the
167	* buffer already exists or is external, the buffer pointers will be
168	* reset to their original state.
169	*/
170	void
171	enable_buffer();
172
173	/**
174	* @brief Destroy internal buffer.
175	*
176	* This function is safe to call multiple times. It will ensure
177	* that the internal buffer is deallocated if it exists. In any
178	* case, it will also reset the buffer pointers.
179	*/
180	void
181	disable_buffer();
182
183	/**
184	* Underlying file pointer.
185	*/
186	gzFile file;
187
188	/**
189	* Mode in which file was opened.
190	*/
191	std::ios_base::openmode io_mode;
192
193	/**
194	* @brief True if this object owns file descriptor.
195	*
196	* This makes the class responsible for closing the file
197	* upon destruction.
198	*/
199	bool own_fd;
200
201	/**
202	* @brief Stream buffer.
203	*
204	* For simplicity this remains allocated on the free store for the
205	* entire life span of the gzfilebuf object, unless replaced by setbuf.
206	*/
207	char_type* buffer;
208
209	/**
210	* @brief Stream buffer size.
211	*
212	* Defaults to system default buffer size (typically 8192 bytes).
213	* Modified by setbuf.
214	*/
215	std::streamsize buffer_size;
216
217	/**
218	* @brief True if this object owns stream buffer.
219	*
220	* This makes the class responsible for deleting the buffer
221	* upon destruction.
222	*/
223	bool own_buffer;
224	};
225
226	/*****************************************************************************/
227
228	/**
229	* @brief Gzipped file input stream class.
230	*
231	* This class implements ifstream for gzipped files. Seeking and putback
232	* is not supported yet.
233	*/
234	class gzifstream : public std::istream
235	{
236	public:
237	// Default constructor
238	gzifstream();
239
240	/**
241	* @brief Construct stream on gzipped file to be opened.
242	* @param name File name.
243	* @param mode Open mode flags (forced to contain ios::in).
244	*/
245	explicit
246	gzifstream(const char* name,
247	std::ios_base::openmode mode = std::ios_base::in);
248
249	/**
250	* @brief Construct stream on already open gzipped file.
251	* @param fd File descriptor.
252	* @param mode Open mode flags (forced to contain ios::in).
253	*/
254	explicit
255	gzifstream(int fd,
256	std::ios_base::openmode mode = std::ios_base::in);
257
258	/**
259	* Obtain underlying stream buffer.
260	*/
261	gzfilebuf*
262	rdbuf() const
263	{ return const_cast<gzfilebuf*>(&sb); }
264
265	/**
266	* @brief Check if file is open.
267	* @return True if file is open.
268	*/
269	bool
270	is_open() { return sb.is_open(); }
271
272	/**
273	* @brief Open gzipped file.
274	* @param name File name.
275	* @param mode Open mode flags (forced to contain ios::in).
276	*
277	* Stream will be in state good() if file opens successfully;
278	* otherwise in state fail(). This differs from the behavior of
279	* ifstream, which never sets the state to good() and therefore
280	* won't allow you to reuse the stream for a second file unless
281	* you manually clear() the state. The choice is a matter of
282	* convenience.
283	*/
284	void
285	open(const char* name,
286	std::ios_base::openmode mode = std::ios_base::in);
287
288	/**
289	* @brief Attach to already open gzipped file.
290	* @param fd File descriptor.
291	* @param mode Open mode flags (forced to contain ios::in).
292	*
293	* Stream will be in state good() if attach succeeded; otherwise
294	* in state fail().
295	*/
296	void
297	attach(int fd,
298	std::ios_base::openmode mode = std::ios_base::in);
299
300	/**
301	* @brief Close gzipped file.
302	*
303	* Stream will be in state fail() if close failed.
304	*/
305	void
306	close();
307
308	private:
309	/**
310	* Underlying stream buffer.
311	*/
312	gzfilebuf sb;
313	};
314
315	/*****************************************************************************/
316
317	/**
318	* @brief Gzipped file output stream class.
319	*
320	* This class implements ofstream for gzipped files. Seeking and putback
321	* is not supported yet.
322	*/
323	class gzofstream : public std::ostream
324	{
325	public:
326	// Default constructor
327	gzofstream();
328
329	/**
330	* @brief Construct stream on gzipped file to be opened.
331	* @param name File name.
332	* @param mode Open mode flags (forced to contain ios::out).
333	*/
334	explicit
335	gzofstream(const char* name,
336	std::ios_base::openmode mode = std::ios_base::out);
337
338	/**
339	* @brief Construct stream on already open gzipped file.
340	* @param fd File descriptor.
341	* @param mode Open mode flags (forced to contain ios::out).
342	*/
343	explicit
344	gzofstream(int fd,
345	std::ios_base::openmode mode = std::ios_base::out);
346
347	/**
348	* Obtain underlying stream buffer.
349	*/
350	gzfilebuf*
351	rdbuf() const
352	{ return const_cast<gzfilebuf*>(&sb); }
353
354	/**
355	* @brief Check if file is open.
356	* @return True if file is open.
357	*/
358	bool
359	is_open() { return sb.is_open(); }
360
361	/**
362	* @brief Open gzipped file.
363	* @param name File name.
364	* @param mode Open mode flags (forced to contain ios::out).
365	*
366	* Stream will be in state good() if file opens successfully;
367	* otherwise in state fail(). This differs from the behavior of
368	* ofstream, which never sets the state to good() and therefore
369	* won't allow you to reuse the stream for a second file unless
370	* you manually clear() the state. The choice is a matter of
371	* convenience.
372	*/
373	void
374	open(const char* name,
375	std::ios_base::openmode mode = std::ios_base::out);
376
377	/**
378	* @brief Attach to already open gzipped file.
379	* @param fd File descriptor.
380	* @param mode Open mode flags (forced to contain ios::out).
381	*
382	* Stream will be in state good() if attach succeeded; otherwise
383	* in state fail().
384	*/
385	void
386	attach(int fd,
387	std::ios_base::openmode mode = std::ios_base::out);
388
389	/**
390	* @brief Close gzipped file.
391	*
392	* Stream will be in state fail() if close failed.
393	*/
394	void
395	close();
396
397	private:
398	/**
399	* Underlying stream buffer.
400	*/
401	gzfilebuf sb;
402	};
403
404	/*****************************************************************************/
405
406	/**
407	* @brief Gzipped file output stream manipulator class.
408	*
409	* This class defines a two-argument manipulator for gzofstream. It is used
410	* as base for the setcompression(int,int) manipulator.
411	*/
412	template<typename T1, typename T2>
413	class gzomanip2
414	{
415	public:
416	// Allows insertor to peek at internals
417	template <typename Ta, typename Tb>
418	friend gzofstream&
419	operator<<(gzofstream&,
420	const gzomanip2<Ta,Tb>&);
421
422	// Constructor
423	gzomanip2(gzofstream& (*f)(gzofstream&, T1, T2),
424	T1 v1,
425	T2 v2);
426	private:
427	// Underlying manipulator function
428	gzofstream&
429	(*func)(gzofstream&, T1, T2);
430
431	// Arguments for manipulator function
432	T1 val1;
433	T2 val2;
434	};
435
436	/*****************************************************************************/
437
438	// Manipulator function thunks through to stream buffer
439	inline gzofstream&
440	setcompression(gzofstream &gzs, int l, int s = Z_DEFAULT_STRATEGY)
441	{
442	(gzs.rdbuf())->setcompression(l, s);
443	return gzs;
444	}
445
446	// Manipulator constructor stores arguments
447	template<typename T1, typename T2>
448	inline
449	gzomanip2<T1,T2>::gzomanip2(gzofstream &(*f)(gzofstream &, T1, T2),
450	T1 v1,
451	T2 v2)
452	: func(f), val1(v1), val2(v2)
453	{ }
454
455	// Insertor applies underlying manipulator function to stream
456	template<typename T1, typename T2>
457	inline gzofstream&
458	operator<<(gzofstream& s, const gzomanip2<T1,T2>& m)
459	{ return (*m.func)(s, m.val1, m.val2); }
460
461	// Insert this onto stream to simplify setting of compression level
462	inline gzomanip2<int,int>
463	setcompression(int l, int s = Z_DEFAULT_STRATEGY)
464	{ return gzomanip2<int,int>(&setcompression, l, s); }
465
466	#endif // ZFSTREAM_H