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[/
/ Copyright (c) 2003-2008 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:Handler Handlers]
A handler must meet the requirements of `CopyConstructible` types (C++ Std,
20.1.3).
In the table below, `X` denotes a handler class, `h` denotes a value of `X`,
`p` denotes a pointer to a block of allocated memory of type `void*`, `s`
denotes the size for a block of allocated memory, and `f` denotes a function
object taking no arguments.
[table Handler requirements
[[expression] [return type] [assertion/note\npre/post-conditions]]
[
[``
using namespace boost::asio;
asio_handler_allocate(s, &h);
``]
[`void*`]
[
Returns a pointer to a block of memory of size `s`. The pointer must
satisfy the same alignment requirements as a pointer returned by
`::operator new()`. Throws `bad_alloc` on failure.\n\n The
`asio_handler_allocate()` function is located using argument-dependent
lookup. The function `boost::asio::asio_handler_allocate()` serves as a
default if no user-supplied function is available.
]
]
[
[``
using namespace boost::asio;
asio_handler_deallocate(p, s, &h);
``]
[]
[
Frees a block of memory associated with a pointer `p`, of at least size
`s`, that was previously allocated using `asio_handler_allocate()`.\n\n The
`asio_handler_deallocate()` function is located using argument-dependent
lookup. The function `boost::asio::asio_handler_deallocate()` serves as a
default if no user-supplied function is available.
]
]
[
[``
using namespace boost::asio;
asio_handler_invoke(f, &h);
``]
[]
[
Causes the function object `f` to be executed as if by calling `f()`.\n\n
The `asio_handler_invoke()` function is located using argument-dependent
lookup. The function `boost::asio::asio_handler_invoke()` serves as a
default if no user-supplied function is available.
]
]
]
[endsect]
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