Added boost header

test/external/boost/asio/read_until.hpp

@@ -0,0 +1,906 @@
+//
+// read_until.hpp
+// ~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2011 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 BOOST_ASIO_READ_UNTIL_HPP
+#define BOOST_ASIO_READ_UNTIL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+
+#if !defined(BOOST_NO_IOSTREAM)
+
+#include <cstddef>
+#include <boost/type_traits/is_function.hpp>
+#include <boost/type_traits/remove_pointer.hpp>
+#include <boost/utility/enable_if.hpp>
+#include <boost/detail/workaround.hpp>
+#include <string>
+#include <boost/asio/basic_streambuf.hpp>
+#include <boost/asio/detail/regex_fwd.hpp>
+#include <boost/asio/error.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+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 = boost::is_function<typename boost::remove_pointer<T>::type>::value
+      || detail::has_result_type<T>::value
+  };
+#endif
+};
+
+/**
+ * @defgroup read_until boost::asio::read_until
+ *
+ * @brief Read data into a streambuf until it contains a delimiter, matches a
+ * regular expression, or a function object indicates a match.
+ */
+/*@{*/
+
+/// 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 boost::system::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 boost::asio::streambuf b;
+ * boost::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
+ * delimiter, so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\n' } @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,
+    boost::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,
+    boost::asio::basic_streambuf<Allocator>& b, char delim,
+    boost::system::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 boost::system::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 boost::asio::streambuf b;
+ * boost::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
+ * delimiter, so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n' } @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,
+    boost::asio::basic_streambuf<Allocator>& b, const std::string& 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,
+    boost::asio::basic_streambuf<Allocator>& b, const std::string& delim,
+    boost::system::error_code& ec);
+
+/// 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 boost::system::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 boost::asio::streambuf b;
+ * boost::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
+ * match, so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n' } @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,
+    boost::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,
+    boost::asio::basic_streambuf<Allocator>& b, const boost::regex& expr,
+    boost::system::error_code& ec);
+
+/// 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 boost::system::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
+ *
+ * @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 boost::asio::buffers_iterator<
+ *     boost::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);
+ * }
+ * ...
+ * boost::asio::streambuf b;
+ * boost::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
+ * ...
+ * boost::asio::streambuf b;
+ * boost::asio::read_until(s, b, match_char('a'));
+ * @endcode
+ */
+template <typename SyncReadStream, typename Allocator, typename MatchCondition>
+std::size_t read_until(SyncReadStream& s,
+    boost::asio::basic_streambuf<Allocator>& b, MatchCondition match_condition,
+    typename boost::enable_if<is_match_condition<MatchCondition> >::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
+ *
+ * @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,
+    boost::asio::basic_streambuf<Allocator>& b,
+    MatchCondition match_condition, boost::system::error_code& ec,
+    typename boost::enable_if<is_match_condition<MatchCondition> >::type* = 0);
+
+/*@}*/
+/**
+ * @defgroup async_read_until boost::asio::async_read_until
+ *
+ * @brief Start an asynchronous operation to read data 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 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 boost::system::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
+ * boost::asio::io_service::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 boost::asio::streambuf b;
+ * ...
+ * void handler(const boost::system::error_code& e, std::size_t size)
+ * {
+ *   if (!e)
+ *   {
+ *     std::istream is(&b);
+ *     std::string line;
+ *     std::getline(is, line);
+ *     ...
+ *   }
+ * }
+ * ...
+ * boost::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
+ * delimiter, so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\n' } @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>
+void async_read_until(AsyncReadStream& s,
+    boost::asio::basic_streambuf<Allocator>& b,
+    char delim, BOOST_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 boost::system::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
+ * boost::asio::io_service::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 boost::asio::streambuf b;
+ * ...
+ * void handler(const boost::system::error_code& e, std::size_t size)
+ * {
+ *   if (!e)
+ *   {
+ *     std::istream is(&b);
+ *     std::string line;
+ *     std::getline(is, line);
+ *     ...
+ *   }
+ * }
+ * ...
+ * boost::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
+ * delimiter, so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n' } @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>
+void async_read_until(AsyncReadStream& s,
+    boost::asio::basic_streambuf<Allocator>& b, const std::string& delim,
+    BOOST_ASIO_MOVE_ARG(ReadHandler) handler);
+
+/// 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 boost::system::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
+ * boost::asio::io_service::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 boost::asio::streambuf b;
+ * ...
+ * void handler(const boost::system::error_code& e, std::size_t size)
+ * {
+ *   if (!e)
+ *   {
+ *     std::istream is(&b);
+ *     std::string line;
+ *     std::getline(is, line);
+ *     ...
+ *   }
+ * }
+ * ...
+ * boost::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
+ * match, so that the string @c line contains:
+ * @code { 'a', 'b', ..., 'c', '\r', '\n' } @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>
+void async_read_until(AsyncReadStream& s,
+    boost::asio::basic_streambuf<Allocator>& b, const boost::regex& expr,
+    BOOST_ASIO_MOVE_ARG(ReadHandler) handler);
+
+/// 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 boost::system::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
+ * boost::asio::io_service::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 boost::asio::buffers_iterator<
+ *     boost::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 boost::system::error_code& e, std::size_t size);
+ * ...
+ * boost::asio::streambuf b;
+ * boost::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 boost::system::error_code& e, std::size_t size);
+ * ...
+ * boost::asio::streambuf b;
+ * boost::asio::async_read_until(s, b, match_char('a'), handler);
+ * @endcode
+ */
+template <typename AsyncReadStream, typename Allocator,
+    typename MatchCondition, typename ReadHandler>
+void async_read_until(AsyncReadStream& s,
+    boost::asio::basic_streambuf<Allocator>& b,
+    MatchCondition match_condition, BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
+    typename boost::enable_if<is_match_condition<MatchCondition> >::type* = 0);
+
+/*@}*/
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#include <boost/asio/impl/read_until.hpp>
+
+#endif // !defined(BOOST_NO_IOSTREAM)
+
+#endif // BOOST_ASIO_READ_UNTIL_HPP