any_completion_handler

Polymorphic wrapper for completion handlers.

template<
    typename... Signatures>
class any_completion_handler

Types

Name	Description
allocator_type	The associated allocator type.
cancellation_slot_type	The associated cancellation slot type.

Member Functions

Name	Description
any_completion_handler [constructor]	Construct an any_completion_handler in an empty state, without a target object. — Construct an any_completion_handler to contain the specified target. — Move-construct an any_completion_handler from another.
get_allocator	Get the associated allocator.
get_cancellation_slot	Get the associated cancellation slot.
operator bool	Test if the polymorphic wrapper is empty.
operator!	Test if the polymorphic wrapper is non-empty.
operator()	Function call operator.
operator=	Move-assign an any_completion_handler from another. — Assignment operator that sets the polymorphic wrapper to the empty state.
swap	Swap the content of an any_completion_handler with another.
~any_completion_handler [destructor]	Destructor.

Friends

Name	Description
operator!=	Inequality operator.
operator==	Equality operator.

The any_completion_handler class template is a polymorphic wrapper for completion handlers that propagates the associated executor, associated allocator, and associated cancellation slot through a type-erasing interface.

When using any_completion_handler, specify one or more completion signatures as template parameters. These will dictate the arguments that may be passed to the handler through the polymorphic interface.

Typical uses for any_completion_handler include:

Separate compilation of asynchronous operation implementations.
Enabling interoperability between asynchronous operations and virtual functions.

Requirements

Header: boost/asio/any_completion_handler.hpp

Convenience header: boost/asio.hpp

Boost C++ Libraries