| // |
| // connect.hpp |
| // ~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2015 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_CONNECT_HPP |
| #define ASIO_CONNECT_HPP |
| |
| |
| #include "asio/detail/config.hpp" |
| #include "asio/async_result.hpp" |
| #include "asio/basic_socket.hpp" |
| #include "asio/error.hpp" |
| |
| #include "asio/detail/push_options.hpp" |
| |
| namespace asio { |
| |
| /** |
| * @defgroup connect asio::connect |
| * |
| * @brief Establishes a socket connection by trying each endpoint in a sequence. |
| */ |
| /*@{*/ |
| |
| /// Establishes a socket connection by trying each endpoint in a sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c connect member |
| * function, once for each endpoint in the sequence, until a connection is |
| * successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @returns On success, an iterator denoting the successfully connected |
| * endpoint. Otherwise, the end iterator. |
| * |
| * @throws asio::system_error Thrown on failure. If the sequence is |
| * empty, the associated @c error_code is asio::error::not_found. |
| * Otherwise, contains the error from the last connection attempt. |
| * |
| * @note This overload assumes that a default constructed object of type @c |
| * Iterator represents the end of the sequence. This is a valid assumption for |
| * iterator types such as @c asio::ip::tcp::resolver::iterator. |
| * |
| * @par Example |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::socket s(io_service); |
| * asio::connect(s, r.resolve(q)); @endcode |
| */ |
| template <typename Protocol, typename SocketService, typename Iterator> |
| Iterator connect(basic_socket<Protocol, SocketService>& s, Iterator begin); |
| |
| /// Establishes a socket connection by trying each endpoint in a sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c connect member |
| * function, once for each endpoint in the sequence, until a connection is |
| * successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @param ec Set to indicate what error occurred, if any. If the sequence is |
| * empty, set to asio::error::not_found. Otherwise, contains the error |
| * from the last connection attempt. |
| * |
| * @returns On success, an iterator denoting the successfully connected |
| * endpoint. Otherwise, the end iterator. |
| * |
| * @note This overload assumes that a default constructed object of type @c |
| * Iterator represents the end of the sequence. This is a valid assumption for |
| * iterator types such as @c asio::ip::tcp::resolver::iterator. |
| * |
| * @par Example |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::socket s(io_service); |
| * asio::error_code ec; |
| * asio::connect(s, r.resolve(q), ec); |
| * if (ec) |
| * { |
| * // An error occurred. |
| * } @endcode |
| */ |
| template <typename Protocol, typename SocketService, typename Iterator> |
| Iterator connect(basic_socket<Protocol, SocketService>& s, |
| Iterator begin, asio::error_code& ec); |
| |
| /// Establishes a socket connection by trying each endpoint in a sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c connect member |
| * function, once for each endpoint in the sequence, until a connection is |
| * successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @param end An iterator pointing to the end of a sequence of endpoints. |
| * |
| * @returns On success, an iterator denoting the successfully connected |
| * endpoint. Otherwise, the end iterator. |
| * |
| * @throws asio::system_error Thrown on failure. If the sequence is |
| * empty, the associated @c error_code is asio::error::not_found. |
| * Otherwise, contains the error from the last connection attempt. |
| * |
| * @par Example |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::resolver::iterator i = r.resolve(q), end; |
| * tcp::socket s(io_service); |
| * asio::connect(s, i, end); @endcode |
| */ |
| template <typename Protocol, typename SocketService, typename Iterator> |
| Iterator connect(basic_socket<Protocol, SocketService>& s, |
| Iterator begin, Iterator end); |
| |
| /// Establishes a socket connection by trying each endpoint in a sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c connect member |
| * function, once for each endpoint in the sequence, until a connection is |
| * successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @param end An iterator pointing to the end of a sequence of endpoints. |
| * |
| * @param ec Set to indicate what error occurred, if any. If the sequence is |
| * empty, set to asio::error::not_found. Otherwise, contains the error |
| * from the last connection attempt. |
| * |
| * @returns On success, an iterator denoting the successfully connected |
| * endpoint. Otherwise, the end iterator. |
| * |
| * @par Example |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::resolver::iterator i = r.resolve(q), end; |
| * tcp::socket s(io_service); |
| * asio::error_code ec; |
| * asio::connect(s, i, end, ec); |
| * if (ec) |
| * { |
| * // An error occurred. |
| * } @endcode |
| */ |
| template <typename Protocol, typename SocketService, typename Iterator> |
| Iterator connect(basic_socket<Protocol, SocketService>& s, |
| Iterator begin, Iterator end, asio::error_code& ec); |
| |
| /// Establishes a socket connection by trying each endpoint in a sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c connect member |
| * function, once for each endpoint in the sequence, until a connection is |
| * successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @param connect_condition A function object that is called prior to each |
| * connection attempt. The signature of the function object must be: |
| * @code Iterator connect_condition( |
| * const asio::error_code& ec, |
| * Iterator next); @endcode |
| * The @c ec parameter contains the result from the most recent connect |
| * operation. Before the first connection attempt, @c ec is always set to |
| * indicate success. The @c next parameter is an iterator pointing to the next |
| * endpoint to be tried. The function object should return the next iterator, |
| * but is permitted to return a different iterator so that endpoints may be |
| * skipped. The implementation guarantees that the function object will never |
| * be called with the end iterator. |
| * |
| * @returns On success, an iterator denoting the successfully connected |
| * endpoint. Otherwise, the end iterator. |
| * |
| * @throws asio::system_error Thrown on failure. If the sequence is |
| * empty, the associated @c error_code is asio::error::not_found. |
| * Otherwise, contains the error from the last connection attempt. |
| * |
| * @note This overload assumes that a default constructed object of type @c |
| * Iterator represents the end of the sequence. This is a valid assumption for |
| * iterator types such as @c asio::ip::tcp::resolver::iterator. |
| * |
| * @par Example |
| * The following connect condition function object can be used to output |
| * information about the individual connection attempts: |
| * @code struct my_connect_condition |
| * { |
| * template <typename Iterator> |
| * Iterator operator()( |
| * const asio::error_code& ec, |
| * Iterator next) |
| * { |
| * if (ec) std::cout << "Error: " << ec.message() << std::endl; |
| * std::cout << "Trying: " << next->endpoint() << std::endl; |
| * return next; |
| * } |
| * }; @endcode |
| * It would be used with the asio::connect function as follows: |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::socket s(io_service); |
| * tcp::resolver::iterator i = asio::connect( |
| * s, r.resolve(q), my_connect_condition()); |
| * std::cout << "Connected to: " << i->endpoint() << std::endl; @endcode |
| */ |
| template <typename Protocol, typename SocketService, |
| typename Iterator, typename ConnectCondition> |
| Iterator connect(basic_socket<Protocol, SocketService>& s, |
| Iterator begin, ConnectCondition connect_condition); |
| |
| /// Establishes a socket connection by trying each endpoint in a sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c connect member |
| * function, once for each endpoint in the sequence, until a connection is |
| * successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @param connect_condition A function object that is called prior to each |
| * connection attempt. The signature of the function object must be: |
| * @code Iterator connect_condition( |
| * const asio::error_code& ec, |
| * Iterator next); @endcode |
| * The @c ec parameter contains the result from the most recent connect |
| * operation. Before the first connection attempt, @c ec is always set to |
| * indicate success. The @c next parameter is an iterator pointing to the next |
| * endpoint to be tried. The function object should return the next iterator, |
| * but is permitted to return a different iterator so that endpoints may be |
| * skipped. The implementation guarantees that the function object will never |
| * be called with the end iterator. |
| * |
| * @param ec Set to indicate what error occurred, if any. If the sequence is |
| * empty, set to asio::error::not_found. Otherwise, contains the error |
| * from the last connection attempt. |
| * |
| * @returns On success, an iterator denoting the successfully connected |
| * endpoint. Otherwise, the end iterator. |
| * |
| * @note This overload assumes that a default constructed object of type @c |
| * Iterator represents the end of the sequence. This is a valid assumption for |
| * iterator types such as @c asio::ip::tcp::resolver::iterator. |
| * |
| * @par Example |
| * The following connect condition function object can be used to output |
| * information about the individual connection attempts: |
| * @code struct my_connect_condition |
| * { |
| * template <typename Iterator> |
| * Iterator operator()( |
| * const asio::error_code& ec, |
| * Iterator next) |
| * { |
| * if (ec) std::cout << "Error: " << ec.message() << std::endl; |
| * std::cout << "Trying: " << next->endpoint() << std::endl; |
| * return next; |
| * } |
| * }; @endcode |
| * It would be used with the asio::connect function as follows: |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::socket s(io_service); |
| * asio::error_code ec; |
| * tcp::resolver::iterator i = asio::connect( |
| * s, r.resolve(q), my_connect_condition(), ec); |
| * if (ec) |
| * { |
| * // An error occurred. |
| * } |
| * else |
| * { |
| * std::cout << "Connected to: " << i->endpoint() << std::endl; |
| * } @endcode |
| */ |
| template <typename Protocol, typename SocketService, |
| typename Iterator, typename ConnectCondition> |
| Iterator connect(basic_socket<Protocol, SocketService>& s, Iterator begin, |
| ConnectCondition connect_condition, asio::error_code& ec); |
| |
| /// Establishes a socket connection by trying each endpoint in a sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c connect member |
| * function, once for each endpoint in the sequence, until a connection is |
| * successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @param end An iterator pointing to the end of a sequence of endpoints. |
| * |
| * @param connect_condition A function object that is called prior to each |
| * connection attempt. The signature of the function object must be: |
| * @code Iterator connect_condition( |
| * const asio::error_code& ec, |
| * Iterator next); @endcode |
| * The @c ec parameter contains the result from the most recent connect |
| * operation. Before the first connection attempt, @c ec is always set to |
| * indicate success. The @c next parameter is an iterator pointing to the next |
| * endpoint to be tried. The function object should return the next iterator, |
| * but is permitted to return a different iterator so that endpoints may be |
| * skipped. The implementation guarantees that the function object will never |
| * be called with the end iterator. |
| * |
| * @returns On success, an iterator denoting the successfully connected |
| * endpoint. Otherwise, the end iterator. |
| * |
| * @throws asio::system_error Thrown on failure. If the sequence is |
| * empty, the associated @c error_code is asio::error::not_found. |
| * Otherwise, contains the error from the last connection attempt. |
| * |
| * @par Example |
| * The following connect condition function object can be used to output |
| * information about the individual connection attempts: |
| * @code struct my_connect_condition |
| * { |
| * template <typename Iterator> |
| * Iterator operator()( |
| * const asio::error_code& ec, |
| * Iterator next) |
| * { |
| * if (ec) std::cout << "Error: " << ec.message() << std::endl; |
| * std::cout << "Trying: " << next->endpoint() << std::endl; |
| * return next; |
| * } |
| * }; @endcode |
| * It would be used with the asio::connect function as follows: |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::resolver::iterator i = r.resolve(q), end; |
| * tcp::socket s(io_service); |
| * i = asio::connect(s, i, end, my_connect_condition()); |
| * std::cout << "Connected to: " << i->endpoint() << std::endl; @endcode |
| */ |
| template <typename Protocol, typename SocketService, |
| typename Iterator, typename ConnectCondition> |
| Iterator connect(basic_socket<Protocol, SocketService>& s, Iterator begin, |
| Iterator end, ConnectCondition connect_condition); |
| |
| /// Establishes a socket connection by trying each endpoint in a sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c connect member |
| * function, once for each endpoint in the sequence, until a connection is |
| * successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @param end An iterator pointing to the end of a sequence of endpoints. |
| * |
| * @param connect_condition A function object that is called prior to each |
| * connection attempt. The signature of the function object must be: |
| * @code Iterator connect_condition( |
| * const asio::error_code& ec, |
| * Iterator next); @endcode |
| * The @c ec parameter contains the result from the most recent connect |
| * operation. Before the first connection attempt, @c ec is always set to |
| * indicate success. The @c next parameter is an iterator pointing to the next |
| * endpoint to be tried. The function object should return the next iterator, |
| * but is permitted to return a different iterator so that endpoints may be |
| * skipped. The implementation guarantees that the function object will never |
| * be called with the end iterator. |
| * |
| * @param ec Set to indicate what error occurred, if any. If the sequence is |
| * empty, set to asio::error::not_found. Otherwise, contains the error |
| * from the last connection attempt. |
| * |
| * @returns On success, an iterator denoting the successfully connected |
| * endpoint. Otherwise, the end iterator. |
| * |
| * @par Example |
| * The following connect condition function object can be used to output |
| * information about the individual connection attempts: |
| * @code struct my_connect_condition |
| * { |
| * template <typename Iterator> |
| * Iterator operator()( |
| * const asio::error_code& ec, |
| * Iterator next) |
| * { |
| * if (ec) std::cout << "Error: " << ec.message() << std::endl; |
| * std::cout << "Trying: " << next->endpoint() << std::endl; |
| * return next; |
| * } |
| * }; @endcode |
| * It would be used with the asio::connect function as follows: |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::resolver::iterator i = r.resolve(q), end; |
| * tcp::socket s(io_service); |
| * asio::error_code ec; |
| * i = asio::connect(s, i, end, my_connect_condition(), ec); |
| * if (ec) |
| * { |
| * // An error occurred. |
| * } |
| * else |
| * { |
| * std::cout << "Connected to: " << i->endpoint() << std::endl; |
| * } @endcode |
| */ |
| template <typename Protocol, typename SocketService, |
| typename Iterator, typename ConnectCondition> |
| Iterator connect(basic_socket<Protocol, SocketService>& s, |
| Iterator begin, Iterator end, ConnectCondition connect_condition, |
| asio::error_code& ec); |
| |
| /*@}*/ |
| |
| /** |
| * @defgroup async_connect asio::async_connect |
| * |
| * @brief Asynchronously establishes a socket connection by trying each |
| * endpoint in a sequence. |
| */ |
| /*@{*/ |
| |
| /// Asynchronously establishes a socket connection by trying each endpoint in a |
| /// sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c async_connect |
| * member function, once for each endpoint in the sequence, until a connection |
| * is successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @param handler The handler to be called when the connect 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. if the sequence is empty, set to |
| * // asio::error::not_found. Otherwise, contains the |
| * // error from the last connection attempt. |
| * const asio::error_code& error, |
| * |
| * // On success, an iterator denoting the successfully |
| * // connected endpoint. Otherwise, the end iterator. |
| * Iterator iterator |
| * ); @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_service::post(). |
| * |
| * @note This overload assumes that a default constructed object of type @c |
| * Iterator represents the end of the sequence. This is a valid assumption for |
| * iterator types such as @c asio::ip::tcp::resolver::iterator. |
| * |
| * @par Example |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::socket s(io_service); |
| * |
| * // ... |
| * |
| * r.async_resolve(q, resolve_handler); |
| * |
| * // ... |
| * |
| * void resolve_handler( |
| * const asio::error_code& ec, |
| * tcp::resolver::iterator i) |
| * { |
| * if (!ec) |
| * { |
| * asio::async_connect(s, i, connect_handler); |
| * } |
| * } |
| * |
| * // ... |
| * |
| * void connect_handler( |
| * const asio::error_code& ec, |
| * tcp::resolver::iterator i) |
| * { |
| * // ... |
| * } @endcode |
| */ |
| template <typename Protocol, typename SocketService, |
| typename Iterator, typename ComposedConnectHandler> |
| ASIO_INITFN_RESULT_TYPE(ComposedConnectHandler, |
| void (asio::error_code, Iterator)) |
| async_connect(basic_socket<Protocol, SocketService>& s, |
| Iterator begin, ASIO_MOVE_ARG(ComposedConnectHandler) handler); |
| |
| /// Asynchronously establishes a socket connection by trying each endpoint in a |
| /// sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c async_connect |
| * member function, once for each endpoint in the sequence, until a connection |
| * is successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @param end An iterator pointing to the end of a sequence of endpoints. |
| * |
| * @param handler The handler to be called when the connect 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. if the sequence is empty, set to |
| * // asio::error::not_found. Otherwise, contains the |
| * // error from the last connection attempt. |
| * const asio::error_code& error, |
| * |
| * // On success, an iterator denoting the successfully |
| * // connected endpoint. Otherwise, the end iterator. |
| * Iterator iterator |
| * ); @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_service::post(). |
| * |
| * @par Example |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::socket s(io_service); |
| * |
| * // ... |
| * |
| * r.async_resolve(q, resolve_handler); |
| * |
| * // ... |
| * |
| * void resolve_handler( |
| * const asio::error_code& ec, |
| * tcp::resolver::iterator i) |
| * { |
| * if (!ec) |
| * { |
| * tcp::resolver::iterator end; |
| * asio::async_connect(s, i, end, connect_handler); |
| * } |
| * } |
| * |
| * // ... |
| * |
| * void connect_handler( |
| * const asio::error_code& ec, |
| * tcp::resolver::iterator i) |
| * { |
| * // ... |
| * } @endcode |
| */ |
| template <typename Protocol, typename SocketService, |
| typename Iterator, typename ComposedConnectHandler> |
| ASIO_INITFN_RESULT_TYPE(ComposedConnectHandler, |
| void (asio::error_code, Iterator)) |
| async_connect(basic_socket<Protocol, SocketService>& s, |
| Iterator begin, Iterator end, |
| ASIO_MOVE_ARG(ComposedConnectHandler) handler); |
| |
| /// Asynchronously establishes a socket connection by trying each endpoint in a |
| /// sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c async_connect |
| * member function, once for each endpoint in the sequence, until a connection |
| * is successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @param connect_condition A function object that is called prior to each |
| * connection attempt. The signature of the function object must be: |
| * @code Iterator connect_condition( |
| * const asio::error_code& ec, |
| * Iterator next); @endcode |
| * The @c ec parameter contains the result from the most recent connect |
| * operation. Before the first connection attempt, @c ec is always set to |
| * indicate success. The @c next parameter is an iterator pointing to the next |
| * endpoint to be tried. The function object should return the next iterator, |
| * but is permitted to return a different iterator so that endpoints may be |
| * skipped. The implementation guarantees that the function object will never |
| * be called with the end iterator. |
| * |
| * @param handler The handler to be called when the connect 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. if the sequence is empty, set to |
| * // asio::error::not_found. Otherwise, contains the |
| * // error from the last connection attempt. |
| * const asio::error_code& error, |
| * |
| * // On success, an iterator denoting the successfully |
| * // connected endpoint. Otherwise, the end iterator. |
| * Iterator iterator |
| * ); @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_service::post(). |
| * |
| * @note This overload assumes that a default constructed object of type @c |
| * Iterator represents the end of the sequence. This is a valid assumption for |
| * iterator types such as @c asio::ip::tcp::resolver::iterator. |
| * |
| * @par Example |
| * The following connect condition function object can be used to output |
| * information about the individual connection attempts: |
| * @code struct my_connect_condition |
| * { |
| * template <typename Iterator> |
| * Iterator operator()( |
| * const asio::error_code& ec, |
| * Iterator next) |
| * { |
| * if (ec) std::cout << "Error: " << ec.message() << std::endl; |
| * std::cout << "Trying: " << next->endpoint() << std::endl; |
| * return next; |
| * } |
| * }; @endcode |
| * It would be used with the asio::connect function as follows: |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::socket s(io_service); |
| * |
| * // ... |
| * |
| * r.async_resolve(q, resolve_handler); |
| * |
| * // ... |
| * |
| * void resolve_handler( |
| * const asio::error_code& ec, |
| * tcp::resolver::iterator i) |
| * { |
| * if (!ec) |
| * { |
| * asio::async_connect(s, i, |
| * my_connect_condition(), |
| * connect_handler); |
| * } |
| * } |
| * |
| * // ... |
| * |
| * void connect_handler( |
| * const asio::error_code& ec, |
| * tcp::resolver::iterator i) |
| * { |
| * if (ec) |
| * { |
| * // An error occurred. |
| * } |
| * else |
| * { |
| * std::cout << "Connected to: " << i->endpoint() << std::endl; |
| * } |
| * } @endcode |
| */ |
| template <typename Protocol, typename SocketService, typename Iterator, |
| typename ConnectCondition, typename ComposedConnectHandler> |
| ASIO_INITFN_RESULT_TYPE(ComposedConnectHandler, |
| void (asio::error_code, Iterator)) |
| async_connect(basic_socket<Protocol, SocketService>& s, Iterator begin, |
| ConnectCondition connect_condition, |
| ASIO_MOVE_ARG(ComposedConnectHandler) handler); |
| |
| /// Asynchronously establishes a socket connection by trying each endpoint in a |
| /// sequence. |
| /** |
| * This function attempts to connect a socket to one of a sequence of |
| * endpoints. It does this by repeated calls to the socket's @c async_connect |
| * member function, once for each endpoint in the sequence, until a connection |
| * is successfully established. |
| * |
| * @param s The socket to be connected. If the socket is already open, it will |
| * be closed. |
| * |
| * @param begin An iterator pointing to the start of a sequence of endpoints. |
| * |
| * @param end An iterator pointing to the end of a sequence of endpoints. |
| * |
| * @param connect_condition A function object that is called prior to each |
| * connection attempt. The signature of the function object must be: |
| * @code Iterator connect_condition( |
| * const asio::error_code& ec, |
| * Iterator next); @endcode |
| * The @c ec parameter contains the result from the most recent connect |
| * operation. Before the first connection attempt, @c ec is always set to |
| * indicate success. The @c next parameter is an iterator pointing to the next |
| * endpoint to be tried. The function object should return the next iterator, |
| * but is permitted to return a different iterator so that endpoints may be |
| * skipped. The implementation guarantees that the function object will never |
| * be called with the end iterator. |
| * |
| * @param handler The handler to be called when the connect 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. if the sequence is empty, set to |
| * // asio::error::not_found. Otherwise, contains the |
| * // error from the last connection attempt. |
| * const asio::error_code& error, |
| * |
| * // On success, an iterator denoting the successfully |
| * // connected endpoint. Otherwise, the end iterator. |
| * Iterator iterator |
| * ); @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_service::post(). |
| * |
| * @par Example |
| * The following connect condition function object can be used to output |
| * information about the individual connection attempts: |
| * @code struct my_connect_condition |
| * { |
| * template <typename Iterator> |
| * Iterator operator()( |
| * const asio::error_code& ec, |
| * Iterator next) |
| * { |
| * if (ec) std::cout << "Error: " << ec.message() << std::endl; |
| * std::cout << "Trying: " << next->endpoint() << std::endl; |
| * return next; |
| * } |
| * }; @endcode |
| * It would be used with the asio::connect function as follows: |
| * @code tcp::resolver r(io_service); |
| * tcp::resolver::query q("host", "service"); |
| * tcp::socket s(io_service); |
| * |
| * // ... |
| * |
| * r.async_resolve(q, resolve_handler); |
| * |
| * // ... |
| * |
| * void resolve_handler( |
| * const asio::error_code& ec, |
| * tcp::resolver::iterator i) |
| * { |
| * if (!ec) |
| * { |
| * tcp::resolver::iterator end; |
| * asio::async_connect(s, i, end, |
| * my_connect_condition(), |
| * connect_handler); |
| * } |
| * } |
| * |
| * // ... |
| * |
| * void connect_handler( |
| * const asio::error_code& ec, |
| * tcp::resolver::iterator i) |
| * { |
| * if (ec) |
| * { |
| * // An error occurred. |
| * } |
| * else |
| * { |
| * std::cout << "Connected to: " << i->endpoint() << std::endl; |
| * } |
| * } @endcode |
| */ |
| template <typename Protocol, typename SocketService, typename Iterator, |
| typename ConnectCondition, typename ComposedConnectHandler> |
| ASIO_INITFN_RESULT_TYPE(ComposedConnectHandler, |
| void (asio::error_code, Iterator)) |
| async_connect(basic_socket<Protocol, SocketService>& s, |
| Iterator begin, Iterator end, ConnectCondition connect_condition, |
| ASIO_MOVE_ARG(ComposedConnectHandler) handler); |
| |
| /*@}*/ |
| |
| } // namespace asio |
| |
| #include "asio/detail/pop_options.hpp" |
| |
| #include "asio/impl/connect.hpp" |
| |
| #endif |