include/boost/capy/read_until.hpp

81.2% Lines (147/181) 85.0% List of functions (34/40) 55.2% Branches (32/58)

[ ] prev/next file n p prev/next uncovered line

f(x) Functions (40)

Function Calls Lines Branches Blocks

Line	Branch	Hits	Source Code
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_READ_UNTIL_HPP
11			#define BOOST_CAPY_READ_UNTIL_HPP
12
13			#include <boost/capy/detail/config.hpp>
14			#include <boost/capy/buffers.hpp>
15			#include <boost/capy/cond.hpp>
16			#include <coroutine>
17			#include <boost/capy/error.hpp>
18			#include <boost/capy/io_result.hpp>
19			#include <boost/capy/io_task.hpp>
20			#include <boost/capy/concept/dynamic_buffer.hpp>
21			#include <boost/capy/concept/match_condition.hpp>
22			#include <boost/capy/concept/read_stream.hpp>
23			#include <boost/capy/ex/io_env.hpp>
24
25			#include <algorithm>
26			#include <cstddef>
27			#include <optional>
28			#include <stop_token>
29			#include <string_view>
30			#include <type_traits>
31
32			namespace boost {
33			namespace capy {
34
35			namespace detail {
36
37			// Linearize a buffer sequence into a string
38			inline
39			std::string
40		✗	linearize_buffers(ConstBufferSequence auto const& data)
41			{
42		✗	std::string linear;
43		✗	linear.reserve(buffer_size(data));
44		✗	auto const end_ = end(data);
45		✗	for(auto it = begin(data); it != end_; ++it)
46		✗	linear.append(
47		✗	static_cast<char const*>(it->data()),
48			it->size());
49		✗	return linear;
50		✗	}
51
52			// Search buffer using a MatchCondition, with single-buffer optimization
53			template<MatchCondition M>
54			std::size_t
55		240x	search_buffer_for_match(
56			ConstBufferSequence auto const& data,
57			M const& match,
58			std::size_t* hint = nullptr)
59			{
60			// Fast path: single buffer - no linearization needed
61	4/8 unsigned long boost::capy::detail::search_buffer_for_match<boost::capy::match_delim, boost::capy::const_buffer>(boost::capy::const_buffer const&, boost::capy::match_delim const&, unsigned long): ✓ Branch 1 taken 202 times. ✗ Branch 2 not taken. unsigned long boost::capy::detail::search_buffer_for_match<boost::capy::read_until_test::testMatchCondition()::match_nth_newline, boost::capy::const_buffer>(boost::capy::const_buffer const&, boost::capy::read_until_test::testMatchCondition()::match_nth_newline const&, unsigned long): ✓ Branch 1 taken 8 times. ✗ Branch 2 not taken. unsigned long boost::capy::detail::search_buffer_for_match<boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#1}, boost::capy::const_buffer>(boost::capy::const_buffer const&, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#1} const&, unsigned long): ✓ Branch 1 taken 28 times. ✗ Branch 2 not taken. unsigned long boost::capy::detail::search_buffer_for_match<boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#2}, boost::capy::const_buffer>(boost::capy::const_buffer const&, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#2} const&, unsigned long): ✓ Branch 1 taken 2 times. ✗ Branch 2 not taken.	240x	if(buffer_length(data) == 1)
62			{
63		240x	auto const& buf = *begin(data);
64		720x	return match(std::string_view(
65		240x	static_cast<char const*>(buf.data()),
66		240x	buf.size()), hint);
67			}
68			// Multiple buffers - linearize
69		✗	return match(linearize_buffers(data), hint);
70			}
71
72			// Implementation coroutine for read_until with MatchCondition
73			template<class Stream, class B, MatchCondition M>
74			io_task<std::size_t>
75	3/4 boost::capy::task<boost::capy::io_result<unsigned long> > boost::capy::detail::read_until_match_impl<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::match_delim>(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&, boost::capy::match_delim, unsigned long): ✓ Branch 1 taken 100 times. boost::capy::task<boost::capy::io_result<unsigned long> > boost::capy::detail::read_until_match_impl<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::match_nth_newline>(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&, boost::capy::read_until_test::testMatchCondition()::match_nth_newline, unsigned long): ✓ Branch 1 taken 6 times. boost::capy::task<boost::capy::io_result<unsigned long> > boost::capy::detail::read_until_match_impl<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#1}>(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#1}, unsigned long): ✓ Branch 1 taken 20 times. boost::capy::task<boost::capy::io_result<unsigned long> > boost::capy::detail::read_until_match_impl<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#2}>(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#2}, unsigned long): ✗ Branch 1 not taken.	126x	read_until_match_impl(
76			Stream& stream,
77			B& buffers,
78			M match,
79			std::size_t initial_amount)
80			{
81			std::size_t amount = initial_amount;
82
83			for(;;)
84			{
85			// Check max_size before preparing
86			if(buffers.size() >= buffers.max_size())
87			co_return {error::not_found, 0};
88
89			// Prepare space, respecting max_size
90			std::size_t const available = buffers.max_size() - buffers.size();
91			std::size_t const to_prepare = (std::min)(amount, available);
92			if(to_prepare == 0)
93			co_return {error::not_found, 0};
94
95			auto mb = buffers.prepare(to_prepare);
96			auto [ec, n] = co_await stream.read_some(mb);
97			buffers.commit(n);
98
99			if(!ec)
100			{
101			auto pos = search_buffer_for_match(buffers.data(), match);
102			if(pos != std::string_view::npos)
103			co_return {{}, pos};
104			}
105
106			if(ec == cond::eof)
107			co_return {error::eof, buffers.size()};
108			if(ec)
109			co_return {ec, buffers.size()};
110
111			// Grow buffer size for next iteration
112			if(n == buffer_size(mb))
113			amount = amount / 2 + amount;
114			}
115		252x	}
116
117			template<class Stream, class B, MatchCondition M, bool OwnsBuffer>
118			struct read_until_awaitable
119			{
120			Stream* stream_;
121			M match_;
122			std::size_t initial_amount_;
123			std::optional<io_result<std::size_t>> immediate_;
124			std::optional<io_task<std::size_t>> inner_;
125
126			using storage_type = std::conditional_t<OwnsBuffer, B, B*>;
127			storage_type buffers_storage_;
128
129		126x	B& buffers() noexcept
130			{
131			if constexpr(OwnsBuffer)
132		126x	return buffers_storage_;
133			else
134		✗	return *buffers_storage_;
135			}
136
137			// Constructor for lvalue (pointer storage)
138		4x	read_until_awaitable(
139			Stream& stream,
140			B* buffers,
141			M match,
142			std::size_t initial_amount)
143			requires (!OwnsBuffer)
144		4x	: stream_(std::addressof(stream))
145		4x	, match_(std::move(match))
146		4x	, initial_amount_(initial_amount)
147		4x	, buffers_storage_(buffers)
148			{
149	1/1 ✓ Branch 1 taken 4 times.	4x	auto pos = search_buffer_for_match(
150		4x	buffers_storage_->data(), match_);
151	1/2 ✓ Branch 0 taken 4 times. ✗ Branch 1 not taken.	4x	if(pos != std::string_view::npos)
152		4x	immediate_.emplace(io_result<std::size_t>{{}, pos});
153		4x	}
154
155			// Constructor for rvalue adapter (owned storage)
156		132x	read_until_awaitable(
157			Stream& stream,
158			B&& buffers,
159			M match,
160			std::size_t initial_amount)
161			requires OwnsBuffer
162		132x	: stream_(std::addressof(stream))
163		132x	, match_(std::move(match))
164		132x	, initial_amount_(initial_amount)
165		132x	, buffers_storage_(std::move(buffers))
166			{
167	4/4 boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::match_delim, true>::read_until_awaitable(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&&, boost::capy::match_delim, unsigned long): ✓ Branch 1 taken 104 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::match_nth_newline, true>::read_until_awaitable(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&&, boost::capy::read_until_test::testMatchCondition()::match_nth_newline, unsigned long): ✓ Branch 1 taken 6 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#1}, true>::read_until_awaitable(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&&, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#1}, unsigned long): ✓ Branch 1 taken 20 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#2}, true>::read_until_awaitable(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&&, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#2}, unsigned long): ✓ Branch 1 taken 2 times.	132x	auto pos = search_buffer_for_match(
168		132x	buffers_storage_.data(), match_);
169	5/8 boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::match_delim, true>::read_until_awaitable(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&&, boost::capy::match_delim, unsigned long): ✓ Branch 0 taken 4 times. ✓ Branch 1 taken 100 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::match_nth_newline, true>::read_until_awaitable(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&&, boost::capy::read_until_test::testMatchCondition()::match_nth_newline, unsigned long): ✗ Branch 0 not taken. ✓ Branch 1 taken 6 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#1}, true>::read_until_awaitable(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&&, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#1}, unsigned long): ✗ Branch 0 not taken. ✓ Branch 1 taken 20 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#2}, true>::read_until_awaitable(boost::capy::test::read_stream&, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >&&, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#2}, unsigned long): ✓ Branch 0 taken 2 times. ✗ Branch 1 not taken.	132x	if(pos != std::string_view::npos)
170		6x	immediate_.emplace(io_result<std::size_t>{{}, pos});
171		132x	}
172
173			bool
174		136x	await_ready() const noexcept
175			{
176		136x	return immediate_.has_value();
177			}
178
179			std::coroutine_handle<>
180		126x	await_suspend(std::coroutine_handle<> h, io_env const* env)
181			{
182		252x	inner_.emplace(read_until_match_impl(
183	3/5 boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::match_delim, false>::await_suspend(std::__n4861::coroutine_handle<void>, boost::capy::io_env const): ✗ Branch 1 not taken. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::match_delim, true>::await_suspend(std::__n4861::coroutine_handle<void>, boost::capy::io_env const): ✓ Branch 1 taken 100 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::match_nth_newline, true>::await_suspend(std::__n4861::coroutine_handle<void>, boost::capy::io_env const): ✓ Branch 1 taken 6 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#1}, true>::await_suspend(std::__n4861::coroutine_handle<void>, boost::capy::io_env const): ✓ Branch 1 taken 20 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#2}, true>::await_suspend(std::__n4861::coroutine_handle<void>, boost::capy::io_env const*): ✗ Branch 1 not taken.	126x	*stream_, buffers(), match_, initial_amount_));
184		126x	return inner_->await_suspend(h, env);
185			}
186
187			io_result<std::size_t>
188		136x	await_resume()
189			{
190	6/10 boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::match_delim, false>::await_resume(): ✓ Branch 1 taken 4 times. ✗ Branch 2 not taken. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::match_delim, true>::await_resume(): ✓ Branch 1 taken 4 times. ✓ Branch 2 taken 100 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::match_nth_newline, true>::await_resume(): ✗ Branch 1 not taken. ✓ Branch 2 taken 6 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#1}, true>::await_resume(): ✗ Branch 1 not taken. ✓ Branch 2 taken 20 times. boost::capy::detail::read_until_awaitable<boost::capy::test::read_stream, boost::capy::basic_string_dynamic_buffer<char, std::char_traits<char>, std::allocator<char> >, boost::capy::read_until_test::testMatchCondition()::{lambda(std::basic_string_view<char, std::char_traits<char> >, unsigned long)#2}, true>::await_resume(): ✓ Branch 1 taken 2 times. ✗ Branch 2 not taken.	136x	if(immediate_)
191		10x	return *immediate_;
192		126x	return inner_->await_resume();
193			}
194			};
195
196			} // namespace detail
197
198			/** Match condition that searches for a delimiter string.
199
200			Satisfies @ref MatchCondition. Returns the position after the
201			delimiter when found, or `npos` otherwise. Provides an overlap
202			hint of `delim.size() - 1` to handle delimiters spanning reads.
203
204			@see MatchCondition, read_until
205			*/
206			struct match_delim
207			{
208			/** The delimiter string to search for.
209
210			@note The referenced characters must remain valid
211			for the lifetime of this object and any pending
212			read operation.
213			*/
214			std::string_view delim;
215
216			/** Search for the delimiter in `data`.
217
218			@param data The data to search.
219			@param hint If non-null, receives the overlap hint
220			on miss.
221			@return `0` if `delim` is empty; otherwise the position
222			just past the delimiter, or `npos` if not found.
223			*/
224			std::size_t
225		202x	operator()(
226			std::string_view data,
227			std::size_t* hint) const noexcept
228			{
229	2/2 ✓ Branch 1 taken 2 times. ✓ Branch 2 taken 200 times.	202x	if(delim.empty())
230		2x	return 0;
231		200x	auto pos = data.find(delim);
232	2/2 ✓ Branch 0 taken 24 times. ✓ Branch 1 taken 176 times.	200x	if(pos != std::string_view::npos)
233		24x	return pos + delim.size();
234	1/2 ✗ Branch 0 not taken. ✓ Branch 1 taken 176 times.	176x	if(hint)
235		✗	*hint = delim.size() > 1 ? delim.size() - 1 : 0;
236		176x	return std::string_view::npos;
237			}
238			};
239
240			/** Asynchronously read until a match condition is satisfied.
241
242			Reads data from the stream into the dynamic buffer until the match
243			condition returns a valid position. Implemented using `read_some`.
244			If the match condition is already satisfied by existing buffer
245			data, returns immediately without I/O.
246
247			@li The operation completes when:
248			@li The match condition returns a valid position
249			@li End-of-stream is reached (`cond::eof`)
250			@li The buffer's `max_size()` is reached (`cond::not_found`)
251			@li An error occurs
252			@li The operation is cancelled
253
254			@par Cancellation
255			Supports cancellation via `stop_token` propagated through the
256			IoAwaitable protocol. When cancelled, returns with `cond::canceled`.
257
258			@param stream The stream to read from. The caller retains ownership.
259			@param buffers The dynamic buffer to append data to. Must remain
260			valid until the operation completes.
261			@param match The match condition callable. Copied into the awaitable.
262			@param initial_amount Initial bytes to read per iteration (default
263			2048). Grows by 1.5x when filled.
264
265			@return An awaitable that await-returns `(error_code, std::size_t)`.
266			On success, `n` is the position returned by the match condition
267			(bytes up to and including the matched delimiter). Compare error
268			codes to conditions:
269			@li `cond::eof` - EOF before match; `n` is buffer size
270			@li `cond::not_found` - `max_size()` reached before match
271			@li `cond::canceled` - Operation was cancelled
272
273			@par Example
274
275			@code
276			task<> read_http_header( ReadStream auto& stream )
277			{
278			std::string header;
279			auto [ec, n] = co_await read_until(
280			stream,
281			string_dynamic_buffer( &header ),
282			[]( std::string_view data, std::size_t* hint ) {
283			auto pos = data.find( "\r\n\r\n" );
284			if( pos != std::string_view::npos )
285			return pos + 4;
286			if( hint )
287			*hint = 3; // partial "\r\n\r" possible
288			return std::string_view::npos;
289			} );
290			if( ec )
291			detail::throw_system_error( ec );
292			// header contains data through "\r\n\r\n"
293			}
294			@endcode
295
296			@see read_some, MatchCondition, DynamicBufferParam
297			*/
298			template<ReadStream Stream, class B, MatchCondition M>
299			requires DynamicBufferParam<B&&>
300			auto
301		136x	read_until(
302			Stream& stream,
303			B&& buffers,
304			M match,
305			std::size_t initial_amount = 2048)
306			{
307		136x	constexpr bool is_lvalue = std::is_lvalue_reference_v<B&&>;
308			using BareB = std::remove_reference_t<B>;
309
310			if constexpr(is_lvalue)
311			return detail::read_until_awaitable<Stream, BareB, M, false>(
312		4x	stream, std::addressof(buffers), std::move(match), initial_amount);
313			else
314			return detail::read_until_awaitable<Stream, BareB, M, true>(
315		132x	stream, std::move(buffers), std::move(match), initial_amount);
316			}
317
318			/** Asynchronously read until a delimiter string is found.
319
320			Reads data from the stream until the delimiter is found. This is
321			a convenience overload equivalent to calling `read_until` with
322			`match_delim{delim}`. If the delimiter already exists in the
323			buffer, returns immediately without I/O.
324
325			@li The operation completes when:
326			@li The delimiter string is found
327			@li End-of-stream is reached (`cond::eof`)
328			@li The buffer's `max_size()` is reached (`cond::not_found`)
329			@li An error occurs
330			@li The operation is cancelled
331
332			@par Cancellation
333			Supports cancellation via `stop_token` propagated through the
334			IoAwaitable protocol. When cancelled, returns with `cond::canceled`.
335
336			@param stream The stream to read from. The caller retains ownership.
337			@param buffers The dynamic buffer to append data to. Must remain
338			valid until the operation completes.
339			@param delim The delimiter string to search for.
340			@param initial_amount Initial bytes to read per iteration (default
341			2048). Grows by 1.5x when filled.
342
343			@return An awaitable that await-returns `(error_code, std::size_t)`.
344			On success, `n` is bytes up to and including the delimiter.
345			Compare error codes to conditions:
346			@li `cond::eof` - EOF before delimiter; `n` is buffer size
347			@li `cond::not_found` - `max_size()` reached before delimiter
348			@li `cond::canceled` - Operation was cancelled
349
350			@par Example
351
352			@code
353			task<std::string> read_line( ReadStream auto& stream )
354			{
355			std::string line;
356			auto [ec, n] = co_await read_until(
357			stream, string_dynamic_buffer( &line ), "\r\n" );
358			if( ec == cond::eof )
359			co_return line; // partial line at EOF
360			if( ec )
361			detail::throw_system_error( ec );
362			line.resize( n - 2 ); // remove "\r\n"
363			co_return line;
364			}
365			@endcode
366
367			@see read_until, match_delim, DynamicBufferParam
368			*/
369			template<ReadStream Stream, class B>
370			requires DynamicBufferParam<B&&>
371			auto
372		108x	read_until(
373			Stream& stream,
374			B&& buffers,
375			std::string_view delim,
376			std::size_t initial_amount = 2048)
377			{
378			return read_until(
379			stream,
380			std::forward<B>(buffers),
381			match_delim{delim},
382		108x	initial_amount);
383			}
384
385			} // namespace capy
386			} // namespace boost
387
388			#endif
389