Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

bind_handler

Bind parameters to a completion handler, creating a new handler.

Synopsis

Defined in header <boost/beast/core/bind_handler.hpp>

template<
    class Handler,
    class... Args>
implementation-defined
bind_handler(
    Handler&& handler,
    Args&&... args);

Description

This function creates a new handler which, when invoked, calls the original handler with the list of bound arguments. Any parameters passed in the invocation will be substituted for placeholders present in the list of bound arguments. Parameters which are not matched to placeholders are silently discarded.

The passed handler and arguments are forwarded into the returned handler, whose associated allocator and associated executor will be the same as those of the original handler.

Example

This function posts the invocation of the specified completion handler with bound arguments:

template < class AsyncReadStream, class ReadHandler>
void
signal_aborted (AsyncReadStream& stream, ReadHandler&& handler)
{
    net::post(
        stream.get_executor(),
        bind_handler (std::forward <ReadHandler> (handler),
            net::error::operation_aborted, 0));
}

Parameters

Name	Description
`handler`	The handler to wrap. The implementation takes ownership of the handler by performing a decay-copy.
`args`	A list of arguments to bind to the handler. The arguments are forwarded into the returned object. These arguments may include placeholders, which will operate in a fashion identical to a call to `std::bind`.