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+//
+// read_until.hpp
+// ~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_READ_UNTIL_HPP
+#define ASIO_READ_UNTIL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cstddef>
+#include <string>
+#include "asio/async_result.hpp"
+#include "asio/detail/regex_fwd.hpp"
+#include "asio/detail/string_view.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/error.hpp"
+
+#if !defined(ASIO_NO_EXTENSIONS)
+# include "asio/basic_streambuf_fwd.hpp"
+#endif // !defined(ASIO_NO_EXTENSIONS)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+namespace detail
+{
+ char (&has_result_type_helper(...))[2];
+
+ template <typename T>
+ char has_result_type_helper(T*, typename T::result_type* = 0);
+
+ template <typename T>
+ struct has_result_type
+ {
+ enum { value = (sizeof((has_result_type_helper)((T*)(0))) == 1) };
+ };
+} // namespace detail
+
+/// Type trait used to determine whether a type can be used as a match condition
+/// function with read_until and async_read_until.
+template <typename T>
+struct is_match_condition
+{
+#if defined(GENERATING_DOCUMENTATION)
+ /// The value member is true if the type may be used as a match condition.
+ static const bool value;
+#else
+ enum
+ {
+ value = asio::is_function<
+ typename asio::remove_pointer<T>::type>::value
+ || detail::has_result_type<T>::value
+ };
+#endif
+};
+
+/**
+ * @defgroup read_until asio::read_until
+ *
+ * @brief Read data into a dynamic buffer sequence, or into a streambuf, until
+ * it contains a delimiter, matches a regular expression, or a function object
+ * indicates a match.
+ */
+/*@{*/
+
+/// Read data into a dynamic buffer sequence until it contains a specified
+/// delimiter.
+/**
+ * This function is used to read data into the specified dynamic buffer
+ * sequence until the dynamic buffer sequence's get area contains the specified
+ * delimiter. The call will block until one of the following conditions is
+ * true:
+ *
+ * @li The get area of the dynamic buffer sequence contains the specified
+ * delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the dynamic buffer sequence's get area already
+ * contains the delimiter, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ *
+ * @param delim The delimiter character.
+ *
+ * @returns The number of bytes in the dynamic buffer sequence's get area up to
+ * and including the delimiter.
+ *
+ * @throws asio::system_error Thrown on failure.
+ *
+ * @note After a successful read_until operation, the dynamic buffer sequence
+ * may contain additional data beyond the delimiter. An application will
+ * typically leave that data in the dynamic buffer sequence for a subsequent
+ * read_until operation to examine.
+ *
+ * @par Example
+ * To read data into a @c std::string until a newline is encountered:
+ * @code std::string data;
+ * std::string n = asio::read_until(s,
+ * asio::dynamic_buffer(data), '\n');
+ * std::string line = data.substr(0, n);
+ * data.erase(0, n); @endcode
+ * After the @c read_until operation completes successfully, the string @c data
+ * contains the delimiter:
+ * @code { 'a', 'b', ..., 'c', '\n', 'd', 'e', ... } @endcode
+ * The call to @c substr then extracts the data up to and including the
+ * delimiter, so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\n' } @endcode
+ * After the call to @c erase, the remaining data is left in the buffer @c b as
+ * follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c read_until operation.
+ */
+template <typename SyncReadStream, typename DynamicBuffer>
+std::size_t read_until(SyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers, char delim);
+
+/// Read data into a dynamic buffer sequence until it contains a specified
+/// delimiter.
+/**
+ * This function is used to read data into the specified dynamic buffer
+ * sequence until the dynamic buffer sequence's get area contains the specified
+ * delimiter. The call will block until one of the following conditions is
+ * true:
+ *
+ * @li The get area of the dynamic buffer sequence contains the specified
+ * delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the dynamic buffer sequence's get area already
+ * contains the delimiter, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ *
+ * @param delim The delimiter character.
+ *
+ * @param ec Set to indicate what error occurred, if any.
+ *
+ * @returns The number of bytes in the dynamic buffer sequence's get area up to
+ * and including the delimiter. Returns 0 if an error occurred.
+ *
+ * @note After a successful read_until operation, the dynamic buffer sequence
+ * may contain additional data beyond the delimiter. An application will
+ * typically leave that data in the dynamic buffer sequence for a subsequent
+ * read_until operation to examine.
+ */
+template <typename SyncReadStream, typename DynamicBuffer>
+std::size_t read_until(SyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ char delim, asio::error_code& ec);
+
+/// Read data into a dynamic buffer sequence until it contains a specified
+/// delimiter.
+/**
+ * This function is used to read data into the specified dynamic buffer
+ * sequence until the dynamic buffer sequence's get area contains the specified
+ * delimiter. The call will block until one of the following conditions is
+ * true:
+ *
+ * @li The get area of the dynamic buffer sequence contains the specified
+ * delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the dynamic buffer sequence's get area already
+ * contains the delimiter, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ *
+ * @param delim The delimiter string.
+ *
+ * @returns The number of bytes in the dynamic buffer sequence's get area up to
+ * and including the delimiter.
+ *
+ * @note After a successful read_until operation, the dynamic buffer sequence
+ * may contain additional data beyond the delimiter. An application will
+ * typically leave that data in the dynamic buffer sequence for a subsequent
+ * read_until operation to examine.
+ *
+ * @par Example
+ * To read data into a @c std::string until a CR-LF sequence is encountered:
+ * @code std::string data;
+ * std::string n = asio::read_until(s,
+ * asio::dynamic_buffer(data), "\r\n");
+ * std::string line = data.substr(0, n);
+ * data.erase(0, n); @endcode
+ * After the @c read_until operation completes successfully, the string @c data
+ * contains the delimiter:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode
+ * The call to @c substr then extracts the data up to and including the
+ * delimiter, so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n' } @endcode
+ * After the call to @c erase, the remaining data is left in the buffer @c b as
+ * follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c read_until operation.
+ */
+template <typename SyncReadStream, typename DynamicBuffer>
+std::size_t read_until(SyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ ASIO_STRING_VIEW_PARAM delim);
+
+/// Read data into a dynamic buffer sequence until it contains a specified
+/// delimiter.
+/**
+ * This function is used to read data into the specified dynamic buffer
+ * sequence until the dynamic buffer sequence's get area contains the specified
+ * delimiter. The call will block until one of the following conditions is
+ * true:
+ *
+ * @li The get area of the dynamic buffer sequence contains the specified
+ * delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the dynamic buffer sequence's get area already
+ * contains the delimiter, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ *
+ * @param delim The delimiter string.
+ *
+ * @param ec Set to indicate what error occurred, if any.
+ *
+ * @returns The number of bytes in the dynamic buffer sequence's get area up to
+ * and including the delimiter. Returns 0 if an error occurred.
+ *
+ * @note After a successful read_until operation, the dynamic buffer sequence
+ * may contain additional data beyond the delimiter. An application will
+ * typically leave that data in the dynamic buffer sequence for a subsequent
+ * read_until operation to examine.
+ */
+template <typename SyncReadStream, typename DynamicBuffer>
+std::size_t read_until(SyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ ASIO_STRING_VIEW_PARAM delim,
+ asio::error_code& ec);
+
+#if !defined(ASIO_NO_EXTENSIONS)
+#if defined(ASIO_HAS_BOOST_REGEX) \
+ || defined(GENERATING_DOCUMENTATION)
+
+/// Read data into a dynamic buffer sequence until some part of the data it
+/// contains matches a regular expression.
+/**
+ * This function is used to read data into the specified dynamic buffer
+ * sequence until the dynamic buffer sequence's get area contains some data
+ * that matches a regular expression. The call will block until one of the
+ * following conditions is true:
+ *
+ * @li A substring of the dynamic buffer sequence's get area matches the
+ * regular expression.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the dynamic buffer sequence's get area already
+ * contains data that matches the regular expression, the function returns
+ * immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers A dynamic buffer sequence into which the data will be read.
+ *
+ * @param expr The regular expression.
+ *
+ * @returns The number of bytes in the dynamic buffer sequence's get area up to
+ * and including the substring that matches the regular expression.
+ *
+ * @throws asio::system_error Thrown on failure.
+ *
+ * @note After a successful read_until operation, the dynamic buffer sequence
+ * may contain additional data beyond that which matched the regular
+ * expression. An application will typically leave that data in the dynamic
+ * buffer sequence for a subsequent read_until operation to examine.
+ *
+ * @par Example
+ * To read data into a @c std::string until a CR-LF sequence is encountered:
+ * @code std::string data;
+ * std::string n = asio::read_until(s,
+ * asio::dynamic_buffer(data), boost::regex("\r\n"));
+ * std::string line = data.substr(0, n);
+ * data.erase(0, n); @endcode
+ * After the @c read_until operation completes successfully, the string @c data
+ * contains the delimiter:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode
+ * The call to @c substr then extracts the data up to and including the
+ * delimiter, so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n' } @endcode
+ * After the call to @c erase, the remaining data is left in the buffer @c b as
+ * follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c read_until operation.
+ */
+template <typename SyncReadStream, typename DynamicBuffer>
+std::size_t read_until(SyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ const boost::regex& expr);
+
+/// Read data into a dynamic buffer sequence until some part of the data it
+/// contains matches a regular expression.
+/**
+ * This function is used to read data into the specified dynamic buffer
+ * sequence until the dynamic buffer sequence's get area contains some data
+ * that matches a regular expression. The call will block until one of the
+ * following conditions is true:
+ *
+ * @li A substring of the dynamic buffer sequence's get area matches the
+ * regular expression.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the dynamic buffer sequence's get area already
+ * contains data that matches the regular expression, the function returns
+ * immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers A dynamic buffer sequence into which the data will be read.
+ *
+ * @param expr The regular expression.
+ *
+ * @param ec Set to indicate what error occurred, if any.
+ *
+ * @returns The number of bytes in the dynamic buffer sequence's get area up to
+ * and including the substring that matches the regular expression. Returns 0
+ * if an error occurred.
+ *
+ * @note After a successful read_until operation, the dynamic buffer sequence
+ * may contain additional data beyond that which matched the regular
+ * expression. An application will typically leave that data in the dynamic
+ * buffer sequence for a subsequent read_until operation to examine.
+ */
+template <typename SyncReadStream, typename DynamicBuffer>
+std::size_t read_until(SyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ const boost::regex& expr, asio::error_code& ec);
+
+#endif // defined(ASIO_HAS_BOOST_REGEX)
+ // || defined(GENERATING_DOCUMENTATION)
+
+/// Read data into a dynamic buffer sequence until a function object indicates a
+/// match.
+
+/**
+ * This function is used to read data into the specified dynamic buffer
+ * sequence until a user-defined match condition function object, when applied
+ * to the data contained in the dynamic buffer sequence, indicates a successful
+ * match. The call will block until one of the following conditions is true:
+ *
+ * @li The match condition function object returns a std::pair where the second
+ * element evaluates to true.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the match condition function object already indicates
+ * a match, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers A dynamic buffer sequence into which the data will be read.
+ *
+ * @param match_condition The function object to be called to determine whether
+ * a match exists. The signature of the function object must be:
+ * @code pair<iterator, bool> match_condition(iterator begin, iterator end);
+ * @endcode
+ * where @c iterator represents the type:
+ * @code buffers_iterator<typename DynamicBuffer::const_buffers_type>
+ * @endcode
+ * The iterator parameters @c begin and @c end define the range of bytes to be
+ * scanned to determine whether there is a match. The @c first member of the
+ * return value is an iterator marking one-past-the-end of the bytes that have
+ * been consumed by the match function. This iterator is used to calculate the
+ * @c begin parameter for any subsequent invocation of the match condition. The
+ * @c second member of the return value is true if a match has been found, false
+ * otherwise.
+ *
+ * @returns The number of bytes in the dynamic_buffer's get area that
+ * have been fully consumed by the match function.
+ *
+ * @throws asio::system_error Thrown on failure.
+ *
+ * @note After a successful read_until operation, the dynamic buffer sequence
+ * may contain additional data beyond that which matched the function object.
+ * An application will typically leave that data in the dynamic buffer sequence
+ * for a subsequent read_until operation to examine.
+
+ * @note The default implementation of the @c is_match_condition type trait
+ * evaluates to true for function pointers and function objects with a
+ * @c result_type typedef. It must be specialised for other user-defined
+ * function objects.
+ *
+ * @par Examples
+ * To read data into a dynamic buffer sequence until whitespace is encountered:
+ * @code typedef asio::buffers_iterator<
+ * asio::const_buffers_1> iterator;
+ *
+ * std::pair<iterator, bool>
+ * match_whitespace(iterator begin, iterator end)
+ * {
+ * iterator i = begin;
+ * while (i != end)
+ * if (std::isspace(*i++))
+ * return std::make_pair(i, true);
+ * return std::make_pair(i, false);
+ * }
+ * ...
+ * std::string data;
+ * asio::read_until(s, data, match_whitespace);
+ * @endcode
+ *
+ * To read data into a @c std::string until a matching character is found:
+ * @code class match_char
+ * {
+ * public:
+ * explicit match_char(char c) : c_(c) {}
+ *
+ * template <typename Iterator>
+ * std::pair<Iterator, bool> operator()(
+ * Iterator begin, Iterator end) const
+ * {
+ * Iterator i = begin;
+ * while (i != end)
+ * if (c_ == *i++)
+ * return std::make_pair(i, true);
+ * return std::make_pair(i, false);
+ * }
+ *
+ * private:
+ * char c_;
+ * };
+ *
+ * namespace asio {
+ * template <> struct is_match_condition<match_char>
+ * : public boost::true_type {};
+ * } // namespace asio
+ * ...
+ * std::string data;
+ * asio::read_until(s, data, match_char('a'));
+ * @endcode
+ */
+template <typename SyncReadStream,
+ typename DynamicBuffer, typename MatchCondition>
+std::size_t read_until(SyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ MatchCondition match_condition,
+ typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0);
+
+/// Read data into a dynamic buffer sequence until a function object indicates a
+/// match.
+/**
+ * This function is used to read data into the specified dynamic buffer
+ * sequence until a user-defined match condition function object, when applied
+ * to the data contained in the dynamic buffer sequence, indicates a successful
+ * match. The call will block until one of the following conditions is true:
+ *
+ * @li The match condition function object returns a std::pair where the second
+ * element evaluates to true.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the match condition function object already indicates
+ * a match, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers A dynamic buffer sequence into which the data will be read.
+ *
+ * @param match_condition The function object to be called to determine whether
+ * a match exists. The signature of the function object must be:
+ * @code pair<iterator, bool> match_condition(iterator begin, iterator end);
+ * @endcode
+ * where @c iterator represents the type:
+ * @code buffers_iterator<DynamicBuffer::const_buffers_type>
+ * @endcode
+ * The iterator parameters @c begin and @c end define the range of bytes to be
+ * scanned to determine whether there is a match. The @c first member of the
+ * return value is an iterator marking one-past-the-end of the bytes that have
+ * been consumed by the match function. This iterator is used to calculate the
+ * @c begin parameter for any subsequent invocation of the match condition. The
+ * @c second member of the return value is true if a match has been found, false
+ * otherwise.
+ *
+ * @param ec Set to indicate what error occurred, if any.
+ *
+ * @returns The number of bytes in the dynamic buffer sequence's get area that
+ * have been fully consumed by the match function. Returns 0 if an error
+ * occurred.
+ *
+ * @note After a successful read_until operation, the dynamic buffer sequence
+ * may contain additional data beyond that which matched the function object.
+ * An application will typically leave that data in the dynamic buffer sequence
+ * for a subsequent read_until operation to examine.
+ *
+ * @note The default implementation of the @c is_match_condition type trait
+ * evaluates to true for function pointers and function objects with a
+ * @c result_type typedef. It must be specialised for other user-defined
+ * function objects.
+ */
+template <typename SyncReadStream,
+ typename DynamicBuffer, typename MatchCondition>
+std::size_t read_until(SyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ MatchCondition match_condition, asio::error_code& ec,
+ typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0);
+
+#if !defined(ASIO_NO_IOSTREAM)
+
+/// Read data into a streambuf until it contains a specified delimiter.
+/**
+ * This function is used to read data into the specified streambuf until the
+ * streambuf's get area contains the specified delimiter. The call will block
+ * until one of the following conditions is true:
+ *
+ * @li The get area of the streambuf contains the specified delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the streambuf's get area already contains the
+ * delimiter, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read.
+ *
+ * @param delim The delimiter character.
+ *
+ * @returns The number of bytes in the streambuf's get area up to and including
+ * the delimiter.
+ *
+ * @throws asio::system_error Thrown on failure.
+ *
+ * @note After a successful read_until operation, the streambuf may contain
+ * additional data beyond the delimiter. An application will typically leave
+ * that data in the streambuf for a subsequent read_until operation to examine.
+ *
+ * @par Example
+ * To read data into a streambuf until a newline is encountered:
+ * @code asio::streambuf b;
+ * asio::read_until(s, b, '\n');
+ * std::istream is(&b);
+ * std::string line;
+ * std::getline(is, line); @endcode
+ * After the @c read_until operation completes successfully, the buffer @c b
+ * contains the delimiter:
+ * @code { 'a', 'b', ..., 'c', '\n', 'd', 'e', ... } @endcode
+ * The call to @c std::getline then extracts the data up to and including the
+ * newline (which is discarded), so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c' } @endcode
+ * The remaining data is left in the buffer @c b as follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c read_until operation.
+ */
+template <typename SyncReadStream, typename Allocator>
+std::size_t read_until(SyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b, char delim);
+
+/// Read data into a streambuf until it contains a specified delimiter.
+/**
+ * This function is used to read data into the specified streambuf until the
+ * streambuf's get area contains the specified delimiter. The call will block
+ * until one of the following conditions is true:
+ *
+ * @li The get area of the streambuf contains the specified delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the streambuf's get area already contains the
+ * delimiter, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read.
+ *
+ * @param delim The delimiter character.
+ *
+ * @param ec Set to indicate what error occurred, if any.
+ *
+ * @returns The number of bytes in the streambuf's get area up to and including
+ * the delimiter. Returns 0 if an error occurred.
+ *
+ * @note After a successful read_until operation, the streambuf may contain
+ * additional data beyond the delimiter. An application will typically leave
+ * that data in the streambuf for a subsequent read_until operation to examine.
+ */
+template <typename SyncReadStream, typename Allocator>
+std::size_t read_until(SyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b, char delim,
+ asio::error_code& ec);
+
+/// Read data into a streambuf until it contains a specified delimiter.
+/**
+ * This function is used to read data into the specified streambuf until the
+ * streambuf's get area contains the specified delimiter. The call will block
+ * until one of the following conditions is true:
+ *
+ * @li The get area of the streambuf contains the specified delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the streambuf's get area already contains the
+ * delimiter, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read.
+ *
+ * @param delim The delimiter string.
+ *
+ * @returns The number of bytes in the streambuf's get area up to and including
+ * the delimiter.
+ *
+ * @throws asio::system_error Thrown on failure.
+ *
+ * @note After a successful read_until operation, the streambuf may contain
+ * additional data beyond the delimiter. An application will typically leave
+ * that data in the streambuf for a subsequent read_until operation to examine.
+ *
+ * @par Example
+ * To read data into a streambuf until a newline is encountered:
+ * @code asio::streambuf b;
+ * asio::read_until(s, b, "\r\n");
+ * std::istream is(&b);
+ * std::string line;
+ * std::getline(is, line); @endcode
+ * After the @c read_until operation completes successfully, the buffer @c b
+ * contains the delimiter:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode
+ * The call to @c std::getline then extracts the data up to and including the
+ * newline (which is discarded), so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r' } @endcode
+ * The remaining data is left in the buffer @c b as follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c read_until operation.
+ */
+template <typename SyncReadStream, typename Allocator>
+std::size_t read_until(SyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b,
+ ASIO_STRING_VIEW_PARAM delim);
+
+/// Read data into a streambuf until it contains a specified delimiter.
+/**
+ * This function is used to read data into the specified streambuf until the
+ * streambuf's get area contains the specified delimiter. The call will block
+ * until one of the following conditions is true:
+ *
+ * @li The get area of the streambuf contains the specified delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the streambuf's get area already contains the
+ * delimiter, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read.
+ *
+ * @param delim The delimiter string.
+ *
+ * @param ec Set to indicate what error occurred, if any.
+ *
+ * @returns The number of bytes in the streambuf's get area up to and including
+ * the delimiter. Returns 0 if an error occurred.
+ *
+ * @note After a successful read_until operation, the streambuf may contain
+ * additional data beyond the delimiter. An application will typically leave
+ * that data in the streambuf for a subsequent read_until operation to examine.
+ */
+template <typename SyncReadStream, typename Allocator>
+std::size_t read_until(SyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b,
+ ASIO_STRING_VIEW_PARAM delim, asio::error_code& ec);
+
+#if defined(ASIO_HAS_BOOST_REGEX) \
+ || defined(GENERATING_DOCUMENTATION)
+
+/// Read data into a streambuf until some part of the data it contains matches
+/// a regular expression.
+/**
+ * This function is used to read data into the specified streambuf until the
+ * streambuf's get area contains some data that matches a regular expression.
+ * The call will block until one of the following conditions is true:
+ *
+ * @li A substring of the streambuf's get area matches the regular expression.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the streambuf's get area already contains data that
+ * matches the regular expression, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read.
+ *
+ * @param expr The regular expression.
+ *
+ * @returns The number of bytes in the streambuf's get area up to and including
+ * the substring that matches the regular expression.
+ *
+ * @throws asio::system_error Thrown on failure.
+ *
+ * @note After a successful read_until operation, the streambuf may contain
+ * additional data beyond that which matched the regular expression. An
+ * application will typically leave that data in the streambuf for a subsequent
+ * read_until operation to examine.
+ *
+ * @par Example
+ * To read data into a streambuf until a CR-LF sequence is encountered:
+ * @code asio::streambuf b;
+ * asio::read_until(s, b, boost::regex("\r\n"));
+ * std::istream is(&b);
+ * std::string line;
+ * std::getline(is, line); @endcode
+ * After the @c read_until operation completes successfully, the buffer @c b
+ * contains the data which matched the regular expression:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode
+ * The call to @c std::getline then extracts the data up to and including the
+ * newline (which is discarded), so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r' } @endcode
+ * The remaining data is left in the buffer @c b as follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c read_until operation.
+ */
+template <typename SyncReadStream, typename Allocator>
+std::size_t read_until(SyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b, const boost::regex& expr);
+
+/// Read data into a streambuf until some part of the data it contains matches
+/// a regular expression.
+/**
+ * This function is used to read data into the specified streambuf until the
+ * streambuf's get area contains some data that matches a regular expression.
+ * The call will block until one of the following conditions is true:
+ *
+ * @li A substring of the streambuf's get area matches the regular expression.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the streambuf's get area already contains data that
+ * matches the regular expression, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read.
+ *
+ * @param expr The regular expression.
+ *
+ * @param ec Set to indicate what error occurred, if any.
+ *
+ * @returns The number of bytes in the streambuf's get area up to and including
+ * the substring that matches the regular expression. Returns 0 if an error
+ * occurred.
+ *
+ * @note After a successful read_until operation, the streambuf may contain
+ * additional data beyond that which matched the regular expression. An
+ * application will typically leave that data in the streambuf for a subsequent
+ * read_until operation to examine.
+ */
+template <typename SyncReadStream, typename Allocator>
+std::size_t read_until(SyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b, const boost::regex& expr,
+ asio::error_code& ec);
+
+#endif // defined(ASIO_HAS_BOOST_REGEX)
+ // || defined(GENERATING_DOCUMENTATION)
+
+/// Read data into a streambuf until a function object indicates a match.
+/**
+ * This function is used to read data into the specified streambuf until a
+ * user-defined match condition function object, when applied to the data
+ * contained in the streambuf, indicates a successful match. The call will
+ * block until one of the following conditions is true:
+ *
+ * @li The match condition function object returns a std::pair where the second
+ * element evaluates to true.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the match condition function object already indicates
+ * a match, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read.
+ *
+ * @param match_condition The function object to be called to determine whether
+ * a match exists. The signature of the function object must be:
+ * @code pair<iterator, bool> match_condition(iterator begin, iterator end);
+ * @endcode
+ * where @c iterator represents the type:
+ * @code buffers_iterator<basic_streambuf<Allocator>::const_buffers_type>
+ * @endcode
+ * The iterator parameters @c begin and @c end define the range of bytes to be
+ * scanned to determine whether there is a match. The @c first member of the
+ * return value is an iterator marking one-past-the-end of the bytes that have
+ * been consumed by the match function. This iterator is used to calculate the
+ * @c begin parameter for any subsequent invocation of the match condition. The
+ * @c second member of the return value is true if a match has been found, false
+ * otherwise.
+ *
+ * @returns The number of bytes in the streambuf's get area that have been fully
+ * consumed by the match function.
+ *
+ * @throws asio::system_error Thrown on failure.
+ *
+ * @note After a successful read_until operation, the streambuf may contain
+ * additional data beyond that which matched the function object. An application
+ * will typically leave that data in the streambuf for a subsequent read_until
+ * operation to examine.
+ *
+ * @note The default implementation of the @c is_match_condition type trait
+ * evaluates to true for function pointers and function objects with a
+ * @c result_type typedef. It must be specialised for other user-defined
+ * function objects.
+ *
+ * @par Examples
+ * To read data into a streambuf until whitespace is encountered:
+ * @code typedef asio::buffers_iterator<
+ * asio::streambuf::const_buffers_type> iterator;
+ *
+ * std::pair<iterator, bool>
+ * match_whitespace(iterator begin, iterator end)
+ * {
+ * iterator i = begin;
+ * while (i != end)
+ * if (std::isspace(*i++))
+ * return std::make_pair(i, true);
+ * return std::make_pair(i, false);
+ * }
+ * ...
+ * asio::streambuf b;
+ * asio::read_until(s, b, match_whitespace);
+ * @endcode
+ *
+ * To read data into a streambuf until a matching character is found:
+ * @code class match_char
+ * {
+ * public:
+ * explicit match_char(char c) : c_(c) {}
+ *
+ * template <typename Iterator>
+ * std::pair<Iterator, bool> operator()(
+ * Iterator begin, Iterator end) const
+ * {
+ * Iterator i = begin;
+ * while (i != end)
+ * if (c_ == *i++)
+ * return std::make_pair(i, true);
+ * return std::make_pair(i, false);
+ * }
+ *
+ * private:
+ * char c_;
+ * };
+ *
+ * namespace asio {
+ * template <> struct is_match_condition<match_char>
+ * : public boost::true_type {};
+ * } // namespace asio
+ * ...
+ * asio::streambuf b;
+ * asio::read_until(s, b, match_char('a'));
+ * @endcode
+ */
+template <typename SyncReadStream, typename Allocator, typename MatchCondition>
+std::size_t read_until(SyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b, MatchCondition match_condition,
+ typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0);
+
+/// Read data into a streambuf until a function object indicates a match.
+/**
+ * This function is used to read data into the specified streambuf until a
+ * user-defined match condition function object, when applied to the data
+ * contained in the streambuf, indicates a successful match. The call will
+ * block until one of the following conditions is true:
+ *
+ * @li The match condition function object returns a std::pair where the second
+ * element evaluates to true.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function. If the match condition function object already indicates
+ * a match, the function returns immediately.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read.
+ *
+ * @param match_condition The function object to be called to determine whether
+ * a match exists. The signature of the function object must be:
+ * @code pair<iterator, bool> match_condition(iterator begin, iterator end);
+ * @endcode
+ * where @c iterator represents the type:
+ * @code buffers_iterator<basic_streambuf<Allocator>::const_buffers_type>
+ * @endcode
+ * The iterator parameters @c begin and @c end define the range of bytes to be
+ * scanned to determine whether there is a match. The @c first member of the
+ * return value is an iterator marking one-past-the-end of the bytes that have
+ * been consumed by the match function. This iterator is used to calculate the
+ * @c begin parameter for any subsequent invocation of the match condition. The
+ * @c second member of the return value is true if a match has been found, false
+ * otherwise.
+ *
+ * @param ec Set to indicate what error occurred, if any.
+ *
+ * @returns The number of bytes in the streambuf's get area that have been fully
+ * consumed by the match function. Returns 0 if an error occurred.
+ *
+ * @note After a successful read_until operation, the streambuf may contain
+ * additional data beyond that which matched the function object. An application
+ * will typically leave that data in the streambuf for a subsequent read_until
+ * operation to examine.
+ *
+ * @note The default implementation of the @c is_match_condition type trait
+ * evaluates to true for function pointers and function objects with a
+ * @c result_type typedef. It must be specialised for other user-defined
+ * function objects.
+ */
+template <typename SyncReadStream, typename Allocator, typename MatchCondition>
+std::size_t read_until(SyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b,
+ MatchCondition match_condition, asio::error_code& ec,
+ typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0);
+
+#endif // !defined(ASIO_NO_IOSTREAM)
+#endif // !defined(ASIO_NO_EXTENSIONS)
+
+/*@}*/
+/**
+ * @defgroup async_read_until asio::async_read_until
+ *
+ * @brief Start an asynchronous operation to read data into a dynamic buffer
+ * sequence, or into a streambuf, until it contains a delimiter, matches a
+ * regular expression, or a function object indicates a match.
+ */
+/*@{*/
+
+/// Start an asynchronous operation to read data into a dynamic buffer sequence
+/// until it contains a specified delimiter.
+/**
+ * This function is used to asynchronously read data into the specified dynamic
+ * buffer sequence until the dynamic buffer sequence's get area contains the
+ * specified delimiter. The function call always returns immediately. The
+ * asynchronous operation will continue until one of the following conditions
+ * is true:
+ *
+ * @li The get area of the dynamic buffer sequence contains the specified
+ * delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * async_read_some function, and is known as a <em>composed operation</em>. If
+ * the dynamic buffer sequence's get area already contains the delimiter, this
+ * asynchronous operation completes immediately. The program must ensure that
+ * the stream performs no other read operations (such as async_read,
+ * async_read_until, the stream's async_read_some function, or any other
+ * composed operations that perform reads) until this operation completes.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the AsyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ * Although the buffers object may be copied as necessary, ownership of the
+ * underlying memory blocks is retained by the caller, which must guarantee
+ * that they remain valid until the handler is called.
+ *
+ * @param delim The delimiter character.
+ *
+ * @param handler The handler to be called when the read operation completes.
+ * Copies will be made of the handler as required. The function signature of the
+ * handler must be:
+ * @code void handler(
+ * // Result of operation.
+ * const asio::error_code& error,
+ *
+ * // The number of bytes in the dynamic buffer sequence's
+ * // get area up to and including the delimiter.
+ * // 0 if an error occurred.
+ * std::size_t bytes_transferred
+ * ); @endcode
+ * Regardless of whether the asynchronous operation completes immediately or
+ * not, the handler will not be invoked from within this function. Invocation of
+ * the handler will be performed in a manner equivalent to using
+ * asio::io_context::post().
+ *
+ * @note After a successful async_read_until operation, the dynamic buffer
+ * sequence may contain additional data beyond the delimiter. An application
+ * will typically leave that data in the dynamic buffer sequence for a
+ * subsequent async_read_until operation to examine.
+ *
+ * @par Example
+ * To asynchronously read data into a @c std::string until a newline is
+ * encountered:
+ * @code std::string data;
+ * ...
+ * void handler(const asio::error_code& e, std::size_t size)
+ * {
+ * if (!e)
+ * {
+ * std::string line = data.substr(0, n);
+ * data.erase(0, n);
+ * ...
+ * }
+ * }
+ * ...
+ * asio::async_read_until(s, data, '\n', handler); @endcode
+ * After the @c async_read_until operation completes successfully, the buffer
+ * @c data contains the delimiter:
+ * @code { 'a', 'b', ..., 'c', '\n', 'd', 'e', ... } @endcode
+ * The call to @c substr then extracts the data up to and including the
+ * delimiter, so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\n' } @endcode
+ * After the call to @c erase, the remaining data is left in the buffer @c data
+ * as follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c async_read_until operation.
+ */
+template <typename AsyncReadStream,
+ typename DynamicBuffer, typename ReadHandler>
+ASIO_INITFN_RESULT_TYPE(ReadHandler,
+ void (asio::error_code, std::size_t))
+async_read_until(AsyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ char delim, ASIO_MOVE_ARG(ReadHandler) handler);
+
+/// Start an asynchronous operation to read data into a dynamic buffer sequence
+/// until it contains a specified delimiter.
+/**
+ * This function is used to asynchronously read data into the specified dynamic
+ * buffer sequence until the dynamic buffer sequence's get area contains the
+ * specified delimiter. The function call always returns immediately. The
+ * asynchronous operation will continue until one of the following conditions
+ * is true:
+ *
+ * @li The get area of the dynamic buffer sequence contains the specified
+ * delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * async_read_some function, and is known as a <em>composed operation</em>. If
+ * the dynamic buffer sequence's get area already contains the delimiter, this
+ * asynchronous operation completes immediately. The program must ensure that
+ * the stream performs no other read operations (such as async_read,
+ * async_read_until, the stream's async_read_some function, or any other
+ * composed operations that perform reads) until this operation completes.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the AsyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ * Although the buffers object may be copied as necessary, ownership of the
+ * underlying memory blocks is retained by the caller, which must guarantee
+ * that they remain valid until the handler is called.
+ *
+ * @param delim The delimiter string.
+ *
+ * @param handler The handler to be called when the read operation completes.
+ * Copies will be made of the handler as required. The function signature of the
+ * handler must be:
+ * @code void handler(
+ * // Result of operation.
+ * const asio::error_code& error,
+ *
+ * // The number of bytes in the dynamic buffer sequence's
+ * // get area up to and including the delimiter.
+ * // 0 if an error occurred.
+ * std::size_t bytes_transferred
+ * ); @endcode
+ * Regardless of whether the asynchronous operation completes immediately or
+ * not, the handler will not be invoked from within this function. Invocation of
+ * the handler will be performed in a manner equivalent to using
+ * asio::io_context::post().
+ *
+ * @note After a successful async_read_until operation, the dynamic buffer
+ * sequence may contain additional data beyond the delimiter. An application
+ * will typically leave that data in the dynamic buffer sequence for a
+ * subsequent async_read_until operation to examine.
+ *
+ * @par Example
+ * To asynchronously read data into a @c std::string until a CR-LF sequence is
+ * encountered:
+ * @code std::string data;
+ * ...
+ * void handler(const asio::error_code& e, std::size_t size)
+ * {
+ * if (!e)
+ * {
+ * std::string line = data.substr(0, n);
+ * data.erase(0, n);
+ * ...
+ * }
+ * }
+ * ...
+ * asio::async_read_until(s, data, "\r\n", handler); @endcode
+ * After the @c async_read_until operation completes successfully, the string
+ * @c data contains the delimiter:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode
+ * The call to @c substr then extracts the data up to and including the
+ * delimiter, so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n' } @endcode
+ * After the call to @c erase, the remaining data is left in the string @c data
+ * as follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c async_read_until operation.
+ */
+template <typename AsyncReadStream,
+ typename DynamicBuffer, typename ReadHandler>
+ASIO_INITFN_RESULT_TYPE(ReadHandler,
+ void (asio::error_code, std::size_t))
+async_read_until(AsyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ ASIO_STRING_VIEW_PARAM delim,
+ ASIO_MOVE_ARG(ReadHandler) handler);
+
+#if !defined(ASIO_NO_EXTENSIONS)
+#if defined(ASIO_HAS_BOOST_REGEX) \
+ || defined(GENERATING_DOCUMENTATION)
+
+/// Start an asynchronous operation to read data into a dynamic buffer sequence
+/// until some part of its data matches a regular expression.
+/**
+ * This function is used to asynchronously read data into the specified dynamic
+ * buffer sequence until the dynamic buffer sequence's get area contains some
+ * data that matches a regular expression. The function call always returns
+ * immediately. The asynchronous operation will continue until one of the
+ * following conditions is true:
+ *
+ * @li A substring of the dynamic buffer sequence's get area matches the regular
+ * expression.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * async_read_some function, and is known as a <em>composed operation</em>. If
+ * the dynamic buffer sequence's get area already contains data that matches
+ * the regular expression, this asynchronous operation completes immediately.
+ * The program must ensure that the stream performs no other read operations
+ * (such as async_read, async_read_until, the stream's async_read_some
+ * function, or any other composed operations that perform reads) until this
+ * operation completes.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the AsyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ * Although the buffers object may be copied as necessary, ownership of the
+ * underlying memory blocks is retained by the caller, which must guarantee
+ * that they remain valid until the handler is called.
+ *
+ * @param expr The regular expression.
+ *
+ * @param handler The handler to be called when the read operation completes.
+ * Copies will be made of the handler as required. The function signature of the
+ * handler must be:
+ * @code void handler(
+ * // Result of operation.
+ * const asio::error_code& error,
+ *
+ * // The number of bytes in the dynamic buffer
+ * // sequence's get area up to and including the
+ * // substring that matches the regular expression.
+ * // 0 if an error occurred.
+ * std::size_t bytes_transferred
+ * ); @endcode
+ * Regardless of whether the asynchronous operation completes immediately or
+ * not, the handler will not be invoked from within this function. Invocation of
+ * the handler will be performed in a manner equivalent to using
+ * asio::io_context::post().
+ *
+ * @note After a successful async_read_until operation, the dynamic buffer
+ * sequence may contain additional data beyond that which matched the regular
+ * expression. An application will typically leave that data in the dynamic
+ * buffer sequence for a subsequent async_read_until operation to examine.
+ *
+ * @par Example
+ * To asynchronously read data into a @c std::string until a CR-LF sequence is
+ * encountered:
+ * @code std::string data;
+ * ...
+ * void handler(const asio::error_code& e, std::size_t size)
+ * {
+ * if (!e)
+ * {
+ * std::string line = data.substr(0, n);
+ * data.erase(0, n);
+ * ...
+ * }
+ * }
+ * ...
+ * asio::async_read_until(s, data,
+ * boost::regex("\r\n"), handler); @endcode
+ * After the @c async_read_until operation completes successfully, the string
+ * @c data contains the data which matched the regular expression:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode
+ * The call to @c substr then extracts the data up to and including the match,
+ * so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n' } @endcode
+ * After the call to @c erase, the remaining data is left in the string @c data
+ * as follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c async_read_until operation.
+ */
+template <typename AsyncReadStream,
+ typename DynamicBuffer, typename ReadHandler>
+ASIO_INITFN_RESULT_TYPE(ReadHandler,
+ void (asio::error_code, std::size_t))
+async_read_until(AsyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ const boost::regex& expr,
+ ASIO_MOVE_ARG(ReadHandler) handler);
+
+#endif // defined(ASIO_HAS_BOOST_REGEX)
+ // || defined(GENERATING_DOCUMENTATION)
+
+/// Start an asynchronous operation to read data into a dynamic buffer sequence
+/// until a function object indicates a match.
+/**
+ * This function is used to asynchronously read data into the specified dynamic
+ * buffer sequence until a user-defined match condition function object, when
+ * applied to the data contained in the dynamic buffer sequence, indicates a
+ * successful match. The function call always returns immediately. The
+ * asynchronous operation will continue until one of the following conditions
+ * is true:
+ *
+ * @li The match condition function object returns a std::pair where the second
+ * element evaluates to true.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * async_read_some function, and is known as a <em>composed operation</em>. If
+ * the match condition function object already indicates a match, this
+ * asynchronous operation completes immediately. The program must ensure that
+ * the stream performs no other read operations (such as async_read,
+ * async_read_until, the stream's async_read_some function, or any other
+ * composed operations that perform reads) until this operation completes.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the AsyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ * Although the buffers object may be copied as necessary, ownership of the
+ * underlying memory blocks is retained by the caller, which must guarantee
+ * that they remain valid until the handler is called.
+ *
+ * @param match_condition The function object to be called to determine whether
+ * a match exists. The signature of the function object must be:
+ * @code pair<iterator, bool> match_condition(iterator begin, iterator end);
+ * @endcode
+ * where @c iterator represents the type:
+ * @code buffers_iterator<typename DynamicBuffer::const_buffers_type>
+ * @endcode
+ * The iterator parameters @c begin and @c end define the range of bytes to be
+ * scanned to determine whether there is a match. The @c first member of the
+ * return value is an iterator marking one-past-the-end of the bytes that have
+ * been consumed by the match function. This iterator is used to calculate the
+ * @c begin parameter for any subsequent invocation of the match condition. The
+ * @c second member of the return value is true if a match has been found, false
+ * otherwise.
+ *
+ * @param handler The handler to be called when the read operation completes.
+ * Copies will be made of the handler as required. The function signature of the
+ * handler must be:
+ * @code void handler(
+ * // Result of operation.
+ * const asio::error_code& error,
+ *
+ * // The number of bytes in the dynamic buffer sequence's
+ * // get area that have been fully consumed by the match
+ * // function. O if an error occurred.
+ * std::size_t bytes_transferred
+ * ); @endcode
+ * Regardless of whether the asynchronous operation completes immediately or
+ * not, the handler will not be invoked from within this function. Invocation of
+ * the handler will be performed in a manner equivalent to using
+ * asio::io_context::post().
+ *
+ * @note After a successful async_read_until operation, the dynamic buffer
+ * sequence may contain additional data beyond that which matched the function
+ * object. An application will typically leave that data in the dynamic buffer
+ * sequence for a subsequent async_read_until operation to examine.
+ *
+ * @note The default implementation of the @c is_match_condition type trait
+ * evaluates to true for function pointers and function objects with a
+ * @c result_type typedef. It must be specialised for other user-defined
+ * function objects.
+ *
+ * @par Examples
+ * To asynchronously read data into a @c std::string until whitespace is
+ * encountered:
+ * @code typedef asio::buffers_iterator<
+ * asio::const_buffers_1> iterator;
+ *
+ * std::pair<iterator, bool>
+ * match_whitespace(iterator begin, iterator end)
+ * {
+ * iterator i = begin;
+ * while (i != end)
+ * if (std::isspace(*i++))
+ * return std::make_pair(i, true);
+ * return std::make_pair(i, false);
+ * }
+ * ...
+ * void handler(const asio::error_code& e, std::size_t size);
+ * ...
+ * std::string data;
+ * asio::async_read_until(s, data, match_whitespace, handler);
+ * @endcode
+ *
+ * To asynchronously read data into a @c std::string until a matching character
+ * is found:
+ * @code class match_char
+ * {
+ * public:
+ * explicit match_char(char c) : c_(c) {}
+ *
+ * template <typename Iterator>
+ * std::pair<Iterator, bool> operator()(
+ * Iterator begin, Iterator end) const
+ * {
+ * Iterator i = begin;
+ * while (i != end)
+ * if (c_ == *i++)
+ * return std::make_pair(i, true);
+ * return std::make_pair(i, false);
+ * }
+ *
+ * private:
+ * char c_;
+ * };
+ *
+ * namespace asio {
+ * template <> struct is_match_condition<match_char>
+ * : public boost::true_type {};
+ * } // namespace asio
+ * ...
+ * void handler(const asio::error_code& e, std::size_t size);
+ * ...
+ * std::string data;
+ * asio::async_read_until(s, data, match_char('a'), handler);
+ * @endcode
+ */
+template <typename AsyncReadStream, typename DynamicBuffer,
+ typename MatchCondition, typename ReadHandler>
+ASIO_INITFN_RESULT_TYPE(ReadHandler,
+ void (asio::error_code, std::size_t))
+async_read_until(AsyncReadStream& s,
+ ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ MatchCondition match_condition, ASIO_MOVE_ARG(ReadHandler) handler,
+ typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0);
+
+#if !defined(ASIO_NO_IOSTREAM)
+
+/// Start an asynchronous operation to read data into a streambuf until it
+/// contains a specified delimiter.
+/**
+ * This function is used to asynchronously read data into the specified
+ * streambuf until the streambuf's get area contains the specified delimiter.
+ * The function call always returns immediately. The asynchronous operation
+ * will continue until one of the following conditions is true:
+ *
+ * @li The get area of the streambuf contains the specified delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * async_read_some function, and is known as a <em>composed operation</em>. If
+ * the streambuf's get area already contains the delimiter, this asynchronous
+ * operation completes immediately. The program must ensure that the stream
+ * performs no other read operations (such as async_read, async_read_until, the
+ * stream's async_read_some function, or any other composed operations that
+ * perform reads) until this operation completes.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the AsyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read. Ownership of
+ * the streambuf is retained by the caller, which must guarantee that it remains
+ * valid until the handler is called.
+ *
+ * @param delim The delimiter character.
+ *
+ * @param handler The handler to be called when the read operation completes.
+ * Copies will be made of the handler as required. The function signature of the
+ * handler must be:
+ * @code void handler(
+ * // Result of operation.
+ * const asio::error_code& error,
+ *
+ * // The number of bytes in the streambuf's get
+ * // area up to and including the delimiter.
+ * // 0 if an error occurred.
+ * std::size_t bytes_transferred
+ * ); @endcode
+ * Regardless of whether the asynchronous operation completes immediately or
+ * not, the handler will not be invoked from within this function. Invocation of
+ * the handler will be performed in a manner equivalent to using
+ * asio::io_context::post().
+ *
+ * @note After a successful async_read_until operation, the streambuf may
+ * contain additional data beyond the delimiter. An application will typically
+ * leave that data in the streambuf for a subsequent async_read_until operation
+ * to examine.
+ *
+ * @par Example
+ * To asynchronously read data into a streambuf until a newline is encountered:
+ * @code asio::streambuf b;
+ * ...
+ * void handler(const asio::error_code& e, std::size_t size)
+ * {
+ * if (!e)
+ * {
+ * std::istream is(&b);
+ * std::string line;
+ * std::getline(is, line);
+ * ...
+ * }
+ * }
+ * ...
+ * asio::async_read_until(s, b, '\n', handler); @endcode
+ * After the @c async_read_until operation completes successfully, the buffer
+ * @c b contains the delimiter:
+ * @code { 'a', 'b', ..., 'c', '\n', 'd', 'e', ... } @endcode
+ * The call to @c std::getline then extracts the data up to and including the
+ * newline (which is discarded), so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c' } @endcode
+ * The remaining data is left in the buffer @c b as follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c async_read_until operation.
+ */
+template <typename AsyncReadStream, typename Allocator, typename ReadHandler>
+ASIO_INITFN_RESULT_TYPE(ReadHandler,
+ void (asio::error_code, std::size_t))
+async_read_until(AsyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b,
+ char delim, ASIO_MOVE_ARG(ReadHandler) handler);
+
+/// Start an asynchronous operation to read data into a streambuf until it
+/// contains a specified delimiter.
+/**
+ * This function is used to asynchronously read data into the specified
+ * streambuf until the streambuf's get area contains the specified delimiter.
+ * The function call always returns immediately. The asynchronous operation
+ * will continue until one of the following conditions is true:
+ *
+ * @li The get area of the streambuf contains the specified delimiter.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * async_read_some function, and is known as a <em>composed operation</em>. If
+ * the streambuf's get area already contains the delimiter, this asynchronous
+ * operation completes immediately. The program must ensure that the stream
+ * performs no other read operations (such as async_read, async_read_until, the
+ * stream's async_read_some function, or any other composed operations that
+ * perform reads) until this operation completes.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the AsyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read. Ownership of
+ * the streambuf is retained by the caller, which must guarantee that it remains
+ * valid until the handler is called.
+ *
+ * @param delim The delimiter string.
+ *
+ * @param handler The handler to be called when the read operation completes.
+ * Copies will be made of the handler as required. The function signature of the
+ * handler must be:
+ * @code void handler(
+ * // Result of operation.
+ * const asio::error_code& error,
+ *
+ * // The number of bytes in the streambuf's get
+ * // area up to and including the delimiter.
+ * // 0 if an error occurred.
+ * std::size_t bytes_transferred
+ * ); @endcode
+ * Regardless of whether the asynchronous operation completes immediately or
+ * not, the handler will not be invoked from within this function. Invocation of
+ * the handler will be performed in a manner equivalent to using
+ * asio::io_context::post().
+ *
+ * @note After a successful async_read_until operation, the streambuf may
+ * contain additional data beyond the delimiter. An application will typically
+ * leave that data in the streambuf for a subsequent async_read_until operation
+ * to examine.
+ *
+ * @par Example
+ * To asynchronously read data into a streambuf until a newline is encountered:
+ * @code asio::streambuf b;
+ * ...
+ * void handler(const asio::error_code& e, std::size_t size)
+ * {
+ * if (!e)
+ * {
+ * std::istream is(&b);
+ * std::string line;
+ * std::getline(is, line);
+ * ...
+ * }
+ * }
+ * ...
+ * asio::async_read_until(s, b, "\r\n", handler); @endcode
+ * After the @c async_read_until operation completes successfully, the buffer
+ * @c b contains the delimiter:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode
+ * The call to @c std::getline then extracts the data up to and including the
+ * newline (which is discarded), so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r' } @endcode
+ * The remaining data is left in the buffer @c b as follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c async_read_until operation.
+ */
+template <typename AsyncReadStream, typename Allocator, typename ReadHandler>
+ASIO_INITFN_RESULT_TYPE(ReadHandler,
+ void (asio::error_code, std::size_t))
+async_read_until(AsyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b,
+ ASIO_STRING_VIEW_PARAM delim,
+ ASIO_MOVE_ARG(ReadHandler) handler);
+
+#if defined(ASIO_HAS_BOOST_REGEX) \
+ || defined(GENERATING_DOCUMENTATION)
+
+/// Start an asynchronous operation to read data into a streambuf until some
+/// part of its data matches a regular expression.
+/**
+ * This function is used to asynchronously read data into the specified
+ * streambuf until the streambuf's get area contains some data that matches a
+ * regular expression. The function call always returns immediately. The
+ * asynchronous operation will continue until one of the following conditions
+ * is true:
+ *
+ * @li A substring of the streambuf's get area matches the regular expression.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * async_read_some function, and is known as a <em>composed operation</em>. If
+ * the streambuf's get area already contains data that matches the regular
+ * expression, this asynchronous operation completes immediately. The program
+ * must ensure that the stream performs no other read operations (such as
+ * async_read, async_read_until, the stream's async_read_some function, or any
+ * other composed operations that perform reads) until this operation
+ * completes.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the AsyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read. Ownership of
+ * the streambuf is retained by the caller, which must guarantee that it remains
+ * valid until the handler is called.
+ *
+ * @param expr The regular expression.
+ *
+ * @param handler The handler to be called when the read operation completes.
+ * Copies will be made of the handler as required. The function signature of the
+ * handler must be:
+ * @code void handler(
+ * // Result of operation.
+ * const asio::error_code& error,
+ *
+ * // The number of bytes in the streambuf's get
+ * // area up to and including the substring
+ * // that matches the regular. expression.
+ * // 0 if an error occurred.
+ * std::size_t bytes_transferred
+ * ); @endcode
+ * Regardless of whether the asynchronous operation completes immediately or
+ * not, the handler will not be invoked from within this function. Invocation of
+ * the handler will be performed in a manner equivalent to using
+ * asio::io_context::post().
+ *
+ * @note After a successful async_read_until operation, the streambuf may
+ * contain additional data beyond that which matched the regular expression. An
+ * application will typically leave that data in the streambuf for a subsequent
+ * async_read_until operation to examine.
+ *
+ * @par Example
+ * To asynchronously read data into a streambuf until a CR-LF sequence is
+ * encountered:
+ * @code asio::streambuf b;
+ * ...
+ * void handler(const asio::error_code& e, std::size_t size)
+ * {
+ * if (!e)
+ * {
+ * std::istream is(&b);
+ * std::string line;
+ * std::getline(is, line);
+ * ...
+ * }
+ * }
+ * ...
+ * asio::async_read_until(s, b, boost::regex("\r\n"), handler); @endcode
+ * After the @c async_read_until operation completes successfully, the buffer
+ * @c b contains the data which matched the regular expression:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode
+ * The call to @c std::getline then extracts the data up to and including the
+ * newline (which is discarded), so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r' } @endcode
+ * The remaining data is left in the buffer @c b as follows:
+ * @code { 'd', 'e', ... } @endcode
+ * This data may be the start of a new line, to be extracted by a subsequent
+ * @c async_read_until operation.
+ */
+template <typename AsyncReadStream, typename Allocator, typename ReadHandler>
+ASIO_INITFN_RESULT_TYPE(ReadHandler,
+ void (asio::error_code, std::size_t))
+async_read_until(AsyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b, const boost::regex& expr,
+ ASIO_MOVE_ARG(ReadHandler) handler);
+
+#endif // defined(ASIO_HAS_BOOST_REGEX)
+ // || defined(GENERATING_DOCUMENTATION)
+
+/// Start an asynchronous operation to read data into a streambuf until a
+/// function object indicates a match.
+/**
+ * This function is used to asynchronously read data into the specified
+ * streambuf until a user-defined match condition function object, when applied
+ * to the data contained in the streambuf, indicates a successful match. The
+ * function call always returns immediately. The asynchronous operation will
+ * continue until one of the following conditions is true:
+ *
+ * @li The match condition function object returns a std::pair where the second
+ * element evaluates to true.
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * async_read_some function, and is known as a <em>composed operation</em>. If
+ * the match condition function object already indicates a match, this
+ * asynchronous operation completes immediately. The program must ensure that
+ * the stream performs no other read operations (such as async_read,
+ * async_read_until, the stream's async_read_some function, or any other
+ * composed operations that perform reads) until this operation completes.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the AsyncReadStream concept.
+ *
+ * @param b A streambuf object into which the data will be read.
+ *
+ * @param match_condition The function object to be called to determine whether
+ * a match exists. The signature of the function object must be:
+ * @code pair<iterator, bool> match_condition(iterator begin, iterator end);
+ * @endcode
+ * where @c iterator represents the type:
+ * @code buffers_iterator<basic_streambuf<Allocator>::const_buffers_type>
+ * @endcode
+ * The iterator parameters @c begin and @c end define the range of bytes to be
+ * scanned to determine whether there is a match. The @c first member of the
+ * return value is an iterator marking one-past-the-end of the bytes that have
+ * been consumed by the match function. This iterator is used to calculate the
+ * @c begin parameter for any subsequent invocation of the match condition. The
+ * @c second member of the return value is true if a match has been found, false
+ * otherwise.
+ *
+ * @param handler The handler to be called when the read operation completes.
+ * Copies will be made of the handler as required. The function signature of the
+ * handler must be:
+ * @code void handler(
+ * // Result of operation.
+ * const asio::error_code& error,
+ *
+ * // The number of bytes in the streambuf's get
+ * // area that have been fully consumed by the
+ * // match function. O if an error occurred.
+ * std::size_t bytes_transferred
+ * ); @endcode
+ * Regardless of whether the asynchronous operation completes immediately or
+ * not, the handler will not be invoked from within this function. Invocation of
+ * the handler will be performed in a manner equivalent to using
+ * asio::io_context::post().
+ *
+ * @note After a successful async_read_until operation, the streambuf may
+ * contain additional data beyond that which matched the function object. An
+ * application will typically leave that data in the streambuf for a subsequent
+ * async_read_until operation to examine.
+ *
+ * @note The default implementation of the @c is_match_condition type trait
+ * evaluates to true for function pointers and function objects with a
+ * @c result_type typedef. It must be specialised for other user-defined
+ * function objects.
+ *
+ * @par Examples
+ * To asynchronously read data into a streambuf until whitespace is encountered:
+ * @code typedef asio::buffers_iterator<
+ * asio::streambuf::const_buffers_type> iterator;
+ *
+ * std::pair<iterator, bool>
+ * match_whitespace(iterator begin, iterator end)
+ * {
+ * iterator i = begin;
+ * while (i != end)
+ * if (std::isspace(*i++))
+ * return std::make_pair(i, true);
+ * return std::make_pair(i, false);
+ * }
+ * ...
+ * void handler(const asio::error_code& e, std::size_t size);
+ * ...
+ * asio::streambuf b;
+ * asio::async_read_until(s, b, match_whitespace, handler);
+ * @endcode
+ *
+ * To asynchronously read data into a streambuf until a matching character is
+ * found:
+ * @code class match_char
+ * {
+ * public:
+ * explicit match_char(char c) : c_(c) {}
+ *
+ * template <typename Iterator>
+ * std::pair<Iterator, bool> operator()(
+ * Iterator begin, Iterator end) const
+ * {
+ * Iterator i = begin;
+ * while (i != end)
+ * if (c_ == *i++)
+ * return std::make_pair(i, true);
+ * return std::make_pair(i, false);
+ * }
+ *
+ * private:
+ * char c_;
+ * };
+ *
+ * namespace asio {
+ * template <> struct is_match_condition<match_char>
+ * : public boost::true_type {};
+ * } // namespace asio
+ * ...
+ * void handler(const asio::error_code& e, std::size_t size);
+ * ...
+ * asio::streambuf b;
+ * asio::async_read_until(s, b, match_char('a'), handler);
+ * @endcode
+ */
+template <typename AsyncReadStream, typename Allocator,
+ typename MatchCondition, typename ReadHandler>
+ASIO_INITFN_RESULT_TYPE(ReadHandler,
+ void (asio::error_code, std::size_t))
+async_read_until(AsyncReadStream& s,
+ asio::basic_streambuf<Allocator>& b,
+ MatchCondition match_condition, ASIO_MOVE_ARG(ReadHandler) handler,
+ typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0);
+
+#endif // !defined(ASIO_NO_IOSTREAM)
+#endif // !defined(ASIO_NO_EXTENSIONS)
+
+/*@}*/
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#include "asio/impl/read_until.hpp"
+
+#endif // ASIO_READ_UNTIL_HPP