[/
 / Copyright (c) 2003-2020 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:Endpoint Endpoint requirements]

A type `X` meets the `Endpoint` requirements if it satisfies the requirements
of `Destructible` (C++Std [destructible]), `DefaultConstructible` (C++Std
[defaultconstructible]), `CopyConstructible` (C++Std [copyconstructible]),
and `CopyAssignable` (C++Std [copyassignable]), as well as the additional
requirements listed below.

The default constructor and move operations of the type `X` shall not exit via
an exception.

In the table below, `a` denotes a (possibly const) value of type `X`, and `u`
denotes an identifier.

[table Endpoint requirements
  [[expression] [type] [assertion/note[br]pre/post-conditions]]
  [
    [`X::protocol_type`]
    [type meeting [link boost_asio.reference.Protocol `Protocol`] requirements]
    []
  ]
  [
    [`a.protocol()`]
    [`protocol_type`]
    []
  ]
]

In the table below, `a` denotes a (possibly const) value of type `X`, `b`
denotes a value of type `X`, and `s` denotes a (possibly const) value of a type
that is convertible to `size_t` and denotes a size in bytes.

[table Endpoint requirements for extensible implementations
  [[expression] [type] [assertion/note[br]pre/post-conditions]]
  [
    [`a.data()`]
    [`const void*`]
    [
      Returns a pointer suitable for passing as the /address/ argument to
      functions such as __POSIX__ __connect__, or as the /dest_addr/ argument
      to functions such as  __POSIX__ __sendto__. The implementation shall
      perform a `static_cast` on the pointer to convert it to `const
      sockaddr*`.
    ]
  ]
  [
    [`b.data()`]
    [`void*`]
    [
      Returns a pointer suitable for passing as the /address/ argument to
      functions such as __POSIX__ __accept__, __getpeername__, __getsockname__
      and __recvfrom__. The implementation shall perform a `static_cast` on the
      pointer to convert it to `sockaddr*`.
    ]
  ]
  [
    [`a.size()`]
    [`size_t`]
    [
      Returns a value suitable for passing as the /address_len/ argument
      to functions such as __POSIX__ __connect__, or as the /dest_len/ argument
      to functions such as __POSIX__ __sendto__, after appropriate integer
      conversion has been performed.
    ]
  ]
  [
    [`b.resize(s)`]
    []
    [
      pre: `s >= 0`[br]
      post: `a.size() == s`[br]
      Passed the value contained in the /address_len/ argument to functions
      such as __POSIX__ __accept__, __getpeername__, __getsockname__ and
      __recvfrom__, after successful completion of the function. Permitted to
      throw an exception if the protocol associated with the endpoint object
      `a` does not support the specified size.
    ]
  ]
  [
    [`a.capacity()`]
    [`size_t`]
    [
      Returns a value suitable for passing as the /address_len/ argument to
      functions such as __POSIX__ __accept__, __getpeername__, __getsockname__
      and __recvfrom__, after appropriate integer conversion has been performed.
    ]
  ]
]

[endsect]