[/
 / Copyright (c) 2003-2016 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)
 /]

[section:SerialPortService Serial port service requirements]

A serial port service must meet the requirements for an [link
boost_asio.reference.IoObjectService I/O object service] with support for movability,
as well as the additional requirements listed below.

In the table below, `X` denotes a serial port service class, `a` and `ao` denote
values of type `X`, `d` denotes a serial port device name of type `std::string`,
`b` and `c` denote values of type `X::implementation_type`, `n` denotes a value
of type `X::native_handle_type`, `ec` denotes a value of type `error_code`, `s`
denotes a value meeting [link boost_asio.reference.SettableSerialPortOption
`SettableSerialPortOption`] requirements, `g` denotes a value meeting [link
boost_asio.reference.GettableSerialPortOption `GettableSerialPortOption`]
requirements, `mb` denotes a value satisfying [link
boost_asio.reference.MutableBufferSequence mutable buffer sequence] requirements,
`rh` denotes a value meeting [link boost_asio.reference.ReadHandler `ReadHandler`]
requirements, `cb` denotes a value satisfying [link
boost_asio.reference.ConstBufferSequence constant buffer sequence] requirements, and
`wh` denotes a value meeting [link boost_asio.reference.WriteHandler `WriteHandler`]
requirements. and `u` and `v` denote identifiers.

[table SerialPortService requirements
  [[expression] [return type] [assertion/note\npre/post-condition]]
  [
    [`X::native_handle_type`]
    []
    [
      The implementation-defined native representation of a serial port. Must
      satisfy the requirements of `CopyConstructible` types (C++ Std, 20.1.3),
      and the requirements of `Assignable` types (C++ Std, 23.1).
    ]
  ]
  [
    [`a.construct(b);`]
    []
    [
      From [link boost_asio.reference.IoObjectService IoObjectService]
      requirements.\n
      post: `!a.is_open(b)`.
    ]
  ]
  [
    [`a.destroy(b);`]
    []
    [
      From [link boost_asio.reference.IoObjectService IoObjectService]
      requirements. Implicitly cancels asynchronous operations, as if by calling
      `a.close(b, ec)`.
    ]
  ]
  [
    [``
      a.move_construct(b, c);
    ``]
    []
    [
      From [link boost_asio.reference.IoObjectService IoObjectService] requirements.
      The underlying native representation is moved from `c` to `b`.
    ]
  ]
  [
    [``
      a.move_assign(b, ao, c);
    ``]
    []
    [
      From [link boost_asio.reference.IoObjectService IoObjectService] requirements.
      Implicitly cancels asynchronous operations associated with `b`, as if by
      calling `a.close(b, ec)`. Then the underlying native representation is
      moved from `c` to `b`.
    ]
  ]
  [
    [``
      const std::string& u = d;
      a.open(b, u, ec);
    ``]
    [`error_code`]
    [
      pre: `!a.is_open(b)`.\n
      post: `!!ec || a.is_open(b)`.
    ]
  ]
  [
    [``
      a.assign(b, n, ec);
    ``]
    [`error_code`]
    [
      pre: `!a.is_open(b)`.\n
      post: `!!ec || a.is_open(b)`.
    ]
  ]
  [
    [``
      a.is_open(b);
    ``]
    [`bool`]
    [
    ]
  ]
  [
    [``
      const X& u = a;
      const X::implementation_type& v = b;
      u.is_open(v);
    ``]
    [`bool`]
    [
    ]
  ]
  [
    [``
      a.close(b, ec);
    ``]
    [`error_code`]
    [
      If `a.is_open()` is true, causes any outstanding asynchronous operations
      to complete as soon as possible. Handlers for cancelled operations shall
      be passed the error code `error::operation_aborted`.\n
      post: `!a.is_open(b)`.
    ]
  ]
  [
    [``
      a.native_handle(b);
    ``]
    [`X::native_handle_type`]
    [
    ]
  ]
  [
    [``
      a.cancel(b, ec);
    ``]
    [`error_code`]
    [
      pre: `a.is_open(b)`.\n
      Causes any outstanding asynchronous operations to complete as soon as
      possible. Handlers for cancelled operations shall be passed the error
      code `error::operation_aborted`.
    ]
  ]
  [
    [``
      a.set_option(b, s, ec);
    ``]
    [`error_code`]
    [
      pre: `a.is_open(b)`.
    ]
  ]
  [
    [``
      a.get_option(b, g, ec);
    ``]
    [`error_code`]
    [
      pre: `a.is_open(b)`.
    ]
  ]
  [
    [``
      const X& u = a;
      const X::implementation_type& v = b;
      u.get_option(v, g, ec);
    ``]
    [`error_code`]
    [
      pre: `a.is_open(b)`.
    ]
  ]
  [
    [``
      a.send_break(b, ec);
    ``]
    [`error_code`]
    [
      pre: `a.is_open(b)`.
    ]
  ]
  [
    [`a.read_some(b, mb, ec);`]
    [`size_t`]
    [
      pre: `a.is_open(b)`.\n
      \n
      Reads one or more bytes of data from a serial port `b`.\n
      \n
      The mutable buffer sequence `mb` specifies memory where the data should
      be placed. The operation shall always fill a buffer in the sequence
      completely before proceeding to the next.\n
      \n
      If successful, returns the number of bytes read. Otherwise returns `0`.
      If the total size of all buffers in the sequence `mb` is `0`, the
      function shall return `0` immediately.\n
      \n
      If the operation completes due to graceful connection closure by the
      peer, the operation shall fail with `error::eof`.
    ]
  ]
  [
    [`a.async_read_some(b, mb, rh);`]
    [`void`]
    [
      pre: `a.is_open(b)`.\n
      \n
      Initiates an asynchronous operation to read one or more bytes of data
      from a serial port `b`. The operation is performed via the
      `io_service` object `a.get_io_service()` and behaves according to [link
      boost_asio.reference.asynchronous_operations asynchronous operation]
      requirements.\n
      \n
      The mutable buffer sequence `mb` specifies memory where the data should
      be placed. The operation shall always fill a buffer in the sequence
      completely before proceeding to the next.\n
      \n
      The implementation shall maintain one or more copies of `mb` until such
      time as the read operation no longer requires access to the memory
      specified by the buffers in the sequence. The program must ensure the
      memory is valid until:\n
      \n
      [mdash] the last copy of `mb` is destroyed, or\n
      \n
      [mdash] the handler for the asynchronous operation is invoked,\n
      \n
      whichever comes first. If the total size of all buffers in the sequence
      `mb` is `0`, the asynchronous read operation shall complete immediately
      and pass `0` as the argument to the handler that specifies the number of
      bytes read.\n
      \n
      If the operation completes due to graceful connection closure by the
      peer, the operation shall fail with `error::eof`.\n
      \n
      If the operation completes successfully, the `ReadHandler` object
      `rh` is invoked with the number of bytes transferred. Otherwise it is
      invoked with `0`.
    ]
  ]
  [
    [`a.write_some(b, cb, ec);`]
    [`size_t`]
    [
      pre: `a.is_open(b)`.\n
      \n
      Writes one or more bytes of data to a serial port `b`.\n
      \n
      The constant buffer sequence `cb` specifies memory where the data to be
      written is located. The operation shall always write a buffer in the
      sequence completely before proceeding to the next.\n
      \n
      If successful, returns the number of bytes written. Otherwise returns `0`.
      If the total size of all buffers in the sequence `cb` is `0`, the
      function shall return `0` immediately.
    ]
  ]
  [
    [`a.async_write_some(b, cb, wh);`]
    [`void`]
    [
      pre: `a.is_open(b)`.\n
      \n
      Initiates an asynchronous operation to write one or more bytes of data to
      a serial port `b`. The operation is performed via the `io_service`
      object `a.get_io_service()` and behaves according to [link
      boost_asio.reference.asynchronous_operations asynchronous operation]
      requirements.\n
      \n
      The constant buffer sequence `cb` specifies memory where the data to be
      written is located. The operation shall always write a buffer in the
      sequence completely before proceeding to the next.\n
      \n
      The implementation shall maintain one or more copies of `cb` until such
      time as the write operation no longer requires access to the memory
      specified by the buffers in the sequence. The program must ensure the
      memory is valid until:\n
      \n
      [mdash] the last copy of `cb` is destroyed, or\n
      \n
      [mdash] the handler for the asynchronous operation is invoked,\n
      \n
      whichever comes first. If the total size of all buffers in the sequence
      `cb` is `0`, the asynchronous operation shall complete immediately and
      pass `0` as the argument to the handler that specifies the number of
      bytes read.\n
      \n
      If the operation completes successfully, the `WriteHandler` object `wh`
      is invoked with the number of bytes transferred. Otherwise it is invoked
      with `0`.
    ]
  ]
]

[endsect]