include/boost/capy/buffers.hpp

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1			//
2			// Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com)
3			//
4			// Distributed under the Boost Software License, Version 1.0. (See accompanying
5			// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6			//
7			// Official repository: https://github.com/cppalliance/capy
8			//
9
10			#ifndef BOOST_CAPY_BUFFERS_HPP
11			#define BOOST_CAPY_BUFFERS_HPP
12
13			#include <boost/capy/detail/config.hpp>
14			#include <concepts>
15			#include <cstddef>
16			#include <iterator>
17			#include <memory>
18			#include <ranges>
19			#include <type_traits>
20
21			// https://www.boost.org/doc/libs/1_65_0/doc/html/boost_asio/reference/ConstBufferSequence.html
22
23			namespace boost {
24
25			namespace asio {
26			class const_buffer;
27			class mutable_buffer;
28			} // asio
29
30			namespace capy {
31
32			class const_buffer;
33			class mutable_buffer;
34
35			namespace detail {
36
37			// satisfies Asio's buffer constructors, CANNOT be removed!
38			template<class T, std::size_t Extent = (std::size_t)(-1)>
39			class basic_buffer
40			{
41			constexpr auto data() const noexcept ->
42			std::conditional_t<std::is_const_v<T>, void const, void>
43			{
44			return p_;
45			}
46
47			constexpr std::size_t size() const noexcept
48			{
49			return n_;
50			}
51
52			friend class capy::const_buffer;
53			friend class capy::mutable_buffer;
54			friend class asio::const_buffer;
55			friend class asio::mutable_buffer;
56		1196x	basic_buffer() = default;
57		63711x	constexpr basic_buffer(T* p, std::size_t n) noexcept : p_(p), n_(n) {}
58			constexpr basic_buffer<T, (std::size_t)(-1)> subspan(
59			std::size_t, std::size_t = (std::size_t)(-1)) const noexcept;
60
61			T* p_ = nullptr;
62			std::size_t n_ = 0;
63			};
64
65			} // detail
66
67			//------------------------------------------------
68
69			/// Tag type for customizing `buffer_size` via `tag_invoke`.
70			struct size_tag {};
71
72			/// Tag type for customizing slice operations via `tag_invoke`.
73			struct slice_tag {};
74
75			/** Constants for slice customization.
76
77			Passed to `tag_invoke` overloads to specify which portion
78			of a buffer sequence to retain.
79			*/
80			enum class slice_how
81			{
82			/// Remove bytes from the front of the sequence.
83			remove_prefix,
84
85			/// Keep only the first N bytes.
86			keep_prefix
87			};
88
89			//------------------------------------------------
90
91			/** A reference to a contiguous region of writable memory.
92
93			Represents a pointer and size pair for a modifiable byte range.
94			Does not own the memory. Satisfies `MutableBufferSequence` (as a
95			single-element sequence) and is implicitly convertible to
96			`const_buffer`.
97
98			@see const_buffer, MutableBufferSequence
99			*/
100			class mutable_buffer
101			: public detail::basic_buffer<unsigned char>
102			{
103			public:
104			/// Construct an empty buffer.
105		585x	mutable_buffer() = default;
106
107			/// Copy constructor.
108			mutable_buffer(
109			mutable_buffer const&) = default;
110
111			/// Copy assignment.
112			mutable_buffer& operator=(
113			mutable_buffer const&) = default;
114
115			/// Construct from pointer and size.
116		26478x	constexpr mutable_buffer(
117			void* data, std::size_t size) noexcept
118		26478x	: basic_buffer<unsigned char>(
119		26478x	static_cast<unsigned char*>(data), size)
120			{
121		26478x	}
122
123			/// Construct from Asio mutable_buffer.
124			template<class MutableBuffer>
125			requires std::same_as<MutableBuffer, asio::mutable_buffer>
126			constexpr mutable_buffer(
127			MutableBuffer const& b) noexcept
128			: basic_buffer<unsigned char>(
129			static_cast<unsigned char*>(
130			b.data()), b.size())
131			{
132			}
133
134			/// Return a pointer to the memory region.
135		69625x	constexpr void* data() const noexcept
136			{
137		69625x	return p_;
138			}
139
140			/// Return the size in bytes.
141		107318x	constexpr std::size_t size() const noexcept
142			{
143		107318x	return n_;
144			}
145
146			/** Advance the buffer start, shrinking the region.
147
148			@param n Bytes to skip. Clamped to `size()`.
149			*/
150			mutable_buffer&
151		25946x	operator+=(std::size_t n) noexcept
152			{
153	2/2 ✓ Branch 0 taken 17 times. ✓ Branch 1 taken 25929 times.	25946x	if( n > n_)
154		17x	n = n_;
155		25946x	p_ += n;
156		25946x	n_ -= n;
157		25946x	return *this;
158			}
159
160			/// Slice customization point for `tag_invoke`.
161			friend
162			void
163		1335x	tag_invoke(
164			slice_tag const&,
165			mutable_buffer& b,
166			slice_how how,
167			std::size_t n) noexcept
168			{
169		1335x	b.do_slice(how, n);
170		1335x	}
171
172			private:
173		1335x	void do_slice(
174			slice_how how, std::size_t n) noexcept
175			{
176	2/3 ✓ Branch 0 taken 659 times. ✓ Branch 1 taken 676 times. ✗ Branch 2 not taken.	1335x	switch(how)
177			{
178		659x	case slice_how::remove_prefix:
179		659x	*this += n;
180		659x	return;
181
182		676x	case slice_how::keep_prefix:
183	2/2 ✓ Branch 0 taken 584 times. ✓ Branch 1 taken 92 times.	676x	if( n < n_)
184		584x	n_ = n;
185		676x	return;
186			}
187			}
188			};
189
190			//------------------------------------------------
191
192			/** A reference to a contiguous region of read-only memory.
193
194			Represents a pointer and size pair for a non-modifiable byte range.
195			Does not own the memory. Satisfies `ConstBufferSequence` (as a
196			single-element sequence). Implicitly constructible from
197			`mutable_buffer`.
198
199			@see mutable_buffer, ConstBufferSequence
200			*/
201			class const_buffer
202			: public detail::basic_buffer<unsigned char const>
203			{
204			public:
205			/// Construct an empty buffer.
206		611x	const_buffer() = default;
207
208			/// Copy constructor.
209			const_buffer(const_buffer const&) = default;
210
211			/// Copy assignment.
212			const_buffer& operator=(
213			const_buffer const& other) = default;
214
215			/// Construct from pointer and size.
216		21791x	constexpr const_buffer(
217			void const* data, std::size_t size) noexcept
218		21791x	: basic_buffer<unsigned char const>(
219		21791x	static_cast<unsigned char const*>(data), size)
220			{
221		21791x	}
222
223			/// Construct from mutable_buffer.
224		15442x	constexpr const_buffer(
225			mutable_buffer const& b) noexcept
226		15442x	: basic_buffer<unsigned char const>(
227		15442x	static_cast<unsigned char const*>(b.data()), b.size())
228			{
229		15442x	}
230
231			/// Construct from Asio buffer types.
232			template<class ConstBuffer>
233			requires (std::same_as<ConstBuffer, asio::const_buffer> \|\|
234			std::same_as<ConstBuffer, asio::mutable_buffer>)
235			constexpr const_buffer(
236			ConstBuffer const& b) noexcept
237			: basic_buffer<unsigned char const>(
238			static_cast<unsigned char const*>(
239			b.data()), b.size())
240			{
241			}
242
243			/// Return a pointer to the memory region.
244		63200x	constexpr void const* data() const noexcept
245			{
246		63200x	return p_;
247			}
248
249			/// Return the size in bytes.
250		121334x	constexpr std::size_t size() const noexcept
251			{
252		121334x	return n_;
253			}
254
255			/** Advance the buffer start, shrinking the region.
256
257			@param n Bytes to skip. Clamped to `size()`.
258			*/
259			const_buffer&
260		26601x	operator+=(std::size_t n) noexcept
261			{
262	2/2 ✓ Branch 0 taken 16 times. ✓ Branch 1 taken 26585 times.	26601x	if( n > n_)
263		16x	n = n_;
264		26601x	p_ += n;
265		26601x	n_ -= n;
266		26601x	return *this;
267			}
268
269			/// Slice customization point for `tag_invoke`.
270			friend
271			void
272		2640x	tag_invoke(
273			slice_tag const&,
274			const_buffer& b,
275			slice_how how,
276			std::size_t n) noexcept
277			{
278		2640x	b.do_slice(how, n);
279		2640x	}
280
281			private:
282		2640x	void do_slice(
283			slice_how how, std::size_t n) noexcept
284			{
285	2/3 ✓ Branch 0 taken 1313 times. ✓ Branch 1 taken 1327 times. ✗ Branch 2 not taken.	2640x	switch(how)
286			{
287		1313x	case slice_how::remove_prefix:
288		1313x	*this += n;
289		1313x	return;
290
291		1327x	case slice_how::keep_prefix:
292	2/2 ✓ Branch 0 taken 1238 times. ✓ Branch 1 taken 89 times.	1327x	if( n < n_)
293		1238x	n_ = n;
294		1327x	return;
295			}
296			}
297			};
298
299			//------------------------------------------------
300
301			/** Concept for sequences of read-only buffer regions.
302
303			A type satisfies `ConstBufferSequence` if it represents one or more
304			contiguous memory regions that can be read. This includes single
305			buffers (convertible to `const_buffer`) and ranges of buffers.
306
307			@par Syntactic Requirements
308			@li Convertible to `const_buffer`, OR
309			@li A bidirectional range with value type convertible to `const_buffer`
310
311			@see const_buffer, MutableBufferSequence
312			*/
313			template<typename T>
314			concept ConstBufferSequence =
315			std::is_convertible_v<T, const_buffer> \|\| (
316			std::ranges::bidirectional_range<T> &&
317			std::is_convertible_v<std::ranges::range_value_t<T>, const_buffer>);
318
319			/** Concept for sequences of writable buffer regions.
320
321			A type satisfies `MutableBufferSequence` if it represents one or more
322			contiguous memory regions that can be written. This includes single
323			buffers (convertible to `mutable_buffer`) and ranges of buffers.
324			Every `MutableBufferSequence` also satisfies `ConstBufferSequence`.
325
326			@par Syntactic Requirements
327			@li Convertible to `mutable_buffer`, OR
328			@li A bidirectional range with value type convertible to `mutable_buffer`
329
330			@see mutable_buffer, ConstBufferSequence
331			*/
332			template<typename T>
333			concept MutableBufferSequence =
334			std::is_convertible_v<T, mutable_buffer> \|\| (
335			std::ranges::bidirectional_range<T> &&
336			std::is_convertible_v<std::ranges::range_value_t<T>, mutable_buffer>);
337
338			//------------------------------------------------------------------------------
339
340			/** Return an iterator to the first buffer in a sequence.
341
342			Handles single buffers and ranges uniformly. For a single buffer,
343			returns a pointer to it (forming a one-element range).
344			*/
345			constexpr struct begin_mrdocs_workaround_t
346			{
347			template<std::convertible_to<const_buffer> ConvertibleToBuffer>
348		19539x	auto operator()(ConvertibleToBuffer const& b) const noexcept -> ConvertibleToBuffer const*
349			{
350		19539x	return std::addressof(b);
351			}
352
353			template<ConstBufferSequence BS>
354			requires (!std::convertible_to<BS, const_buffer>)
355		55944x	auto operator()(BS const& bs) const noexcept
356			{
357		55944x	return std::ranges::begin(bs);
358			}
359
360			template<ConstBufferSequence BS>
361			requires (!std::convertible_to<BS, const_buffer>)
362		18574x	auto operator()(BS& bs) const noexcept
363			{
364		18574x	return std::ranges::begin(bs);
365			}
366			} begin {};
367
368			/** Return an iterator past the last buffer in a sequence.
369
370			Handles single buffers and ranges uniformly. For a single buffer,
371			returns a pointer one past it.
372			*/
373			constexpr struct end_mrdocs_workaround_t
374			{
375			template<std::convertible_to<const_buffer> ConvertibleToBuffer>
376		19299x	auto operator()(ConvertibleToBuffer const& b) const noexcept -> ConvertibleToBuffer const*
377			{
378		19299x	return std::addressof(b) + 1;
379			}
380
381			template<ConstBufferSequence BS>
382			requires (!std::convertible_to<BS, const_buffer>)
383		48415x	auto operator()(BS const& bs) const noexcept
384			{
385		48415x	return std::ranges::end(bs);
386			}
387
388			template<ConstBufferSequence BS>
389			requires (!std::convertible_to<BS, const_buffer>)
390		18574x	auto operator()(BS& bs) const noexcept
391			{
392		18574x	return std::ranges::end(bs);
393			}
394			} end {};
395
396			//------------------------------------------------------------------------------
397
398			template<ConstBufferSequence CB>
399			std::size_t
400		13285x	tag_invoke(
401			size_tag const&,
402			CB const& bs) noexcept
403			{
404		13285x	std::size_t n = 0;
405		13285x	auto const e = end(bs);
406	44/44 unsigned long boost::capy::tag_invoke<boost::capy::const_buffer [3]>(boost::capy::size_tag const&, boost::capy::const_buffer const (&) [3]): ✓ Branch 1 taken 3 times. ✓ Branch 2 taken 1 time. unsigned long boost::capy::tag_invoke<boost::capy::const_buffer>(boost::capy::size_tag const&, boost::capy::const_buffer const&): ✓ Branch 1 taken 5001 times. ✓ Branch 2 taken 5001 times. unsigned long boost::capy::tag_invoke<boost::capy::consuming_buffers<boost::capy::const_buffer> >(boost::capy::size_tag const&, boost::capy::consuming_buffers<boost::capy::const_buffer> const&): ✓ Branch 2 taken 38 times. ✓ Branch 3 taken 38 times. unsigned long boost::capy::tag_invoke<boost::capy::consuming_buffers<boost::capy::mutable_buffer> >(boost::capy::size_tag const&, boost::capy::consuming_buffers<boost::capy::mutable_buffer> const&): ✓ Branch 2 taken 3 times. ✓ Branch 3 taken 3 times. unsigned long boost::capy::tag_invoke<boost::capy::consuming_buffers<std::array<boost::capy::const_buffer, 2ul> > >(boost::capy::size_tag const&, boost::capy::consuming_buffers<std::array<boost::capy::const_buffer, 2ul> > const&): ✓ Branch 2 taken 28 times. ✓ Branch 3 taken 14 times. unsigned long boost::capy::tag_invoke<boost::capy::consuming_buffers<std::array<boost::capy::mutable_buffer, 2ul> > >(boost::capy::size_tag const&, boost::capy::consuming_buffers<std::array<boost::capy::mutable_buffer, 2ul> > const&): ✓ Branch 2 taken 2 times. ✓ Branch 3 taken 1 time. unsigned long boost::capy::tag_invoke<boost::capy::mutable_buffer [3]>(boost::capy::size_tag const&, boost::capy::mutable_buffer const (&) [3]): ✓ Branch 1 taken 3 times. ✓ Branch 2 taken 1 time. unsigned long boost::capy::tag_invoke<boost::capy::mutable_buffer>(boost::capy::size_tag const&, boost::capy::mutable_buffer const&): ✓ Branch 1 taken 738 times. ✓ Branch 2 taken 738 times. unsigned long boost::capy::tag_invoke<boost::capy::slice_of<std::array<boost::capy::const_buffer, 3ul> > >(boost::capy::size_tag const&, boost::capy::slice_of<std::array<boost::capy::const_buffer, 3ul> > const&): ✓ Branch 2 taken 24 times. ✓ Branch 3 taken 14 times. unsigned long boost::capy::tag_invoke<boost::capy::slice_of<std::span<boost::capy::const_buffer const, 18446744073709551615ul> > >(boost::capy::size_tag const&, boost::capy::slice_of<std::span<boost::capy::const_buffer const, 18446744073709551615ul> > const&): ✓ Branch 2 taken 222 times. ✓ Branch 3 taken 110 times. unsigned long boost::capy::tag_invoke<boost::capy::slice_of<std::span<boost::capy::mutable_buffer const, 18446744073709551615ul> > >(boost::capy::size_tag const&, boost::capy::slice_of<std::span<boost::capy::mutable_buffer const, 18446744073709551615ul> > const&): ✓ Branch 2 taken 222 times. ✓ Branch 3 taken 110 times. unsigned long boost::capy::tag_invoke<boost::capy::slice_of<std::vector<boost::capy::const_buffer, std::allocator<boost::capy::const_buffer> > > >(boost::capy::size_tag const&, boost::capy::slice_of<std::vector<boost::capy::const_buffer, std::allocator<boost::capy::const_buffer> > > const&): ✓ Branch 2 taken 1728 times. ✓ Branch 3 taken 986 times. unsigned long boost::capy::tag_invoke<std::array<boost::capy::const_buffer, 2ul> >(boost::capy::size_tag const&, std::array<boost::capy::const_buffer, 2ul> const&): ✓ Branch 1 taken 5816 times. ✓ Branch 2 taken 2908 times. unsigned long boost::capy::tag_invoke<std::array<boost::capy::const_buffer, 3ul> >(boost::capy::size_tag const&, std::array<boost::capy::const_buffer, 3ul> const&): ✓ Branch 1 taken 6 times. ✓ Branch 2 taken 2 times. unsigned long boost::capy::tag_invoke<std::array<boost::capy::mutable_buffer, 2ul> >(boost::capy::size_tag const&, std::array<boost::capy::mutable_buffer, 2ul> const&): ✓ Branch 1 taken 5676 times. ✓ Branch 2 taken 2838 times. unsigned long boost::capy::tag_invoke<std::array<boost::capy::mutable_buffer, 3ul> >(boost::capy::size_tag const&, std::array<boost::capy::mutable_buffer, 3ul> const&): ✓ Branch 1 taken 3 times. ✓ Branch 2 taken 1 time. unsigned long boost::capy::tag_invoke<std::span<boost::capy::const_buffer const, 18446744073709551615ul> >(boost::capy::size_tag const&, std::span<boost::capy::const_buffer const, 18446744073709551615ul> const&): ✓ Branch 2 taken 357 times. ✓ Branch 3 taken 131 times. unsigned long boost::capy::tag_invoke<std::span<boost::capy::const_buffer, 18446744073709551615ul> >(boost::capy::size_tag const&, std::span<boost::capy::const_buffer, 18446744073709551615ul> const&): ✓ Branch 2 taken 222 times. ✓ Branch 3 taken 222 times. unsigned long boost::capy::tag_invoke<std::span<boost::capy::const_buffer, 3ul> >(boost::capy::size_tag const&, std::span<boost::capy::const_buffer, 3ul> const&): ✓ Branch 2 taken 3 times. ✓ Branch 3 taken 1 time. unsigned long boost::capy::tag_invoke<std::span<boost::capy::mutable_buffer const, 18446744073709551615ul> >(boost::capy::size_tag const&, std::span<boost::capy::mutable_buffer const, 18446744073709551615ul> const&): ✓ Branch 2 taken 301 times. ✓ Branch 3 taken 163 times. unsigned long boost::capy::tag_invoke<std::span<boost::capy::mutable_buffer, 3ul> >(boost::capy::size_tag const&, std::span<boost::capy::mutable_buffer, 3ul> const&): ✓ Branch 2 taken 3 times. ✓ Branch 3 taken 1 time. unsigned long boost::capy::tag_invoke<std::vector<boost::capy::const_buffer, std::allocator<boost::capy::const_buffer> > >(boost::capy::size_tag const&, std::vector<boost::capy::const_buffer, std::allocator<boost::capy::const_buffer> > const&): ✓ Branch 2 taken 3 times. ✓ Branch 3 taken 1 time.	33687x	for(auto it = begin(bs); it != e; ++it)
407		20402x	n += const_buffer(*it).size();
408		13285x	return n;
409			}
410
411			//------------------------------------------------------------------------------
412
413			/** Return the total byte count across all buffers in a sequence.
414
415			Sums the `size()` of each buffer in the sequence. This differs
416			from `buffer_length` which counts the number of buffer elements.
417
418			@par Example
419			@code
420			std::array<mutable_buffer, 2> bufs = { ... };
421			std::size_t total = buffer_size( bufs ); // sum of both sizes
422			@endcode
423			*/
424			constexpr struct buffer_size_mrdocs_workaround_t
425			{
426			template<ConstBufferSequence CB>
427		18784x	constexpr std::size_t operator()(
428			CB const& bs) const noexcept
429			{
430		18784x	return tag_invoke(size_tag{}, bs);
431			}
432			} buffer_size {};
433
434			/** Check if a buffer sequence contains no data.
435
436			@return `true` if all buffers have size zero or the sequence
437			is empty.
438			*/
439			constexpr struct buffer_empty_mrdocs_workaround_t
440			{
441			template<ConstBufferSequence CB>
442		3208x	constexpr bool operator()(
443			CB const& bs) const noexcept
444			{
445		3208x	auto it = begin(bs);
446		3208x	auto const end_ = end(bs);
447	6/8 bool boost::capy::buffer_empty_mrdocs_workaround_t::operator()<boost::capy::mutable_buffer>(boost::capy::mutable_buffer const&) const: ✓ Branch 0 taken 377 times. ✓ Branch 1 taken 2 times. bool boost::capy::buffer_empty_mrdocs_workaround_t::operator()<std::span<boost::capy::const_buffer const, 18446744073709551615ul> >(std::span<boost::capy::const_buffer const, 18446744073709551615ul> const&) const: ✓ Branch 1 taken 101 times. ✗ Branch 2 not taken. bool boost::capy::buffer_empty_mrdocs_workaround_t::operator()<std::span<boost::capy::const_buffer, 18446744073709551615ul> >(std::span<boost::capy::const_buffer, 18446744073709551615ul> const&) const: ✓ Branch 1 taken 148 times. ✗ Branch 2 not taken. bool boost::capy::buffer_empty_mrdocs_workaround_t::operator()<std::span<boost::capy::mutable_buffer const, 18446744073709551615ul> >(std::span<boost::capy::mutable_buffer const, 18446744073709551615ul> const&) const: ✓ Branch 1 taken 788 times. ✓ Branch 2 taken 3 times.	3233x	while(it != end_)
448			{
449		3221x	const_buffer b(*it++);
450	5/8 bool boost::capy::buffer_empty_mrdocs_workaround_t::operator()<boost::capy::mutable_buffer>(boost::capy::mutable_buffer const&) const: ✓ Branch 1 taken 375 times. ✓ Branch 2 taken 2 times. bool boost::capy::buffer_empty_mrdocs_workaround_t::operator()<std::span<boost::capy::const_buffer const, 18446744073709551615ul> >(std::span<boost::capy::const_buffer const, 18446744073709551615ul> const&) const: ✓ Branch 1 taken 101 times. ✗ Branch 2 not taken. bool boost::capy::buffer_empty_mrdocs_workaround_t::operator()<std::span<boost::capy::const_buffer, 18446744073709551615ul> >(std::span<boost::capy::const_buffer, 18446744073709551615ul> const&) const: ✓ Branch 1 taken 148 times. ✗ Branch 2 not taken. bool boost::capy::buffer_empty_mrdocs_workaround_t::operator()<std::span<boost::capy::mutable_buffer const, 18446744073709551615ul> >(std::span<boost::capy::mutable_buffer const, 18446744073709551615ul> const&) const: ✓ Branch 1 taken 788 times. ✗ Branch 2 not taken.	3221x	if(b.size() != 0)
451		3196x	return false;
452			}
453		12x	return true;
454			}
455			} buffer_empty {};
456
457			//-----------------------------------------------
458
459			namespace detail {
460
461			template<class It>
462			auto
463		240x	length_impl(It first, It last, int)
464			-> decltype(static_cast<std::size_t>(last - first))
465			{
466		240x	return static_cast<std::size_t>(last - first);
467			}
468
469			template<class It>
470			std::size_t
471			length_impl(It first, It last, long)
472			{
473			std::size_t n = 0;
474			while(first != last)
475			{
476			++first;
477			++n;
478			}
479			return n;
480			}
481
482			} // detail
483
484			/** Return the number of buffer elements in a sequence.
485
486			Counts the number of individual buffer objects, not bytes.
487			For a single buffer, returns 1. For a range, returns the
488			distance from `begin` to `end`.
489
490			@see buffer_size
491			*/
492			template<ConstBufferSequence CB>
493			std::size_t
494		240x	buffer_length(CB const& bs)
495			{
496		240x	return detail::length_impl(
497		240x	begin(bs), end(bs), 0);
498			}
499
500			/// Alias for `mutable_buffer` or `const_buffer` based on sequence type.
501			template<typename BS>
502			using buffer_type = std::conditional_t<
503			MutableBufferSequence<BS>,
504			mutable_buffer, const_buffer>;
505
506			} // capy
507			} // boost
508
509			#endif
510