PlantingHandle< BA, DEFAULT > Class Template Reference

#include "lib/opaque-holder.hpp"

Description

template<class BA, class DEFAULT = BA>
class lib::PlantingHandle< BA, DEFAULT >

A handle to allow for safe »remote implantation« of an unknown subclass into a given opaque InPlaceBuffer, without having to disclose the concrete buffer type or size.

Remarks

this copyable value object is especially geared towards use as handle in APIs, allowing a not yet known implementation to implant an agent or collaboration partner into the likewise undisclosed innards of the service exposed.

Warning

the type BA must expose a virtual dtor, since the targeted InPlaceBuffer has to take ownership of the implanted object.

Note

the siz (buffer size) template parameter from #InPlaceBuffer is deliberately not part of the PlantingHandle<BA,DEFAULT> type, since buffer size can be considered an opaque implementation detail. As a consequence, we must capture this size information at construction time and store it at runtime #maxSiz_, to protect against buffer overrun.

See also

OpaqueUncheckedBuffer_test

Definition at line 104 of file record.hpp.

Public Member Functions
template<size_t maxSiz>
	PlantingHandle (InPlaceBuffer< BA, maxSiz, DEFAULT > &targetBuffer)
template<class SUB >
bool	canCreate () const
template<class SUB , typename... ARGS>
SUB &	create (ARGS &&...args)
	Abbreviation for placement new of a subclass SUB into the opaque buffer.
template<class SUB >
SUB &	emplace (SUB &&implementation)
	move-construct an instance of a subclass into the opaque buffer
BA *	get () const

Private Member Functions
template<class SUB >
void	__ensure_can_create ()

Private Attributes
void *	buffer_
size_t	maxSiz_

Member Function Documentation

__ensure_can_create()

void __ensure_can_create ( )

inlineprivate

Helper to ensure the opaque buffer provides sufficient storage

Template Parameters

SUB	actual subclass type to be implanted into the opaque buffer

Definition at line 847 of file opaque-holder.hpp.

Collaboration diagram for PlantingHandle< BA, DEFAULT >:

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The documentation for this class was generated from the following files:

• record.hpp
• opaque-holder.hpp