| [/ |
| / Copyright (c) 2003-2021 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 `MoveConstructible` types (C++Std |
| [moveconstructible]). |
| |
| 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[br]pre/post-conditions]] |
| [ |
| [`` |
| using asio::asio_handler_allocate; |
| 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.[br][br] The |
| `asio_handler_allocate()` function is located using argument-dependent |
| lookup. The function `asio::asio_handler_allocate()` serves as a |
| default if no user-supplied function is available. |
| ] |
| ] |
| [ |
| [`` |
| using asio::asio_handler_deallocate; |
| 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()`.[br][br] The |
| `asio_handler_deallocate()` function is located using argument-dependent |
| lookup. The function `asio::asio_handler_deallocate()` serves as a |
| default if no user-supplied function is available. |
| ] |
| ] |
| [ |
| [`` |
| using asio::asio_handler_invoke; |
| asio_handler_invoke(f, &h); |
| ``] |
| [] |
| [ |
| Causes the function object `f` to be executed as if by calling `f()`.[br][br] |
| The `asio_handler_invoke()` function is located using argument-dependent |
| lookup. The function `asio::asio_handler_invoke()` serves as a |
| default if no user-supplied function is available. |
| ] |
| ] |
| ] |
| |
| [endsect] |