Allocator_TransferNoncopyable< TY, PAR > Class Template Reference

#include "lib/scoped-holder-transfer.hpp"

Description

template<class TY, class PAR = std::allocator<TY>>
class lib::Allocator_TransferNoncopyable< TY, PAR >

Addendum to scoped-holder.hpp for transferring the lifecycle management to another instance.

Using these wrappers within STL vector and similar containers may result in the need to do a re-allocation in response to a request to grow. Obviously such a feature needs support by the objects being wrapped, which should provide an operation for transferring lifecycle management in a controlled fashion. This behaviour is similar to std::auto_ptr, but because we use a separate dedicated operation, we avoid some of the dangers pertaining the use of the latter: just taking the "value" can't kill the managed object.

To implement this feature we need

• a custom allocator to be used by the vector. By default it is built as a thin proxy round std::allocator.
• the noncopyable type to be managed within the vector needs to provide a custom extension point: when the allocator detects the need to transfer control between two instances, it will invoke a free function named transfer_control(TY& from, TY& to) intended to be found by ADL. Note: in case this function throws, it must not have any side effects.
• besides, the noncopyable type needs to provide an operator bool() yielding true iff currently containing an managed object. This is similar to std::unique_ptr or even the behaviour of a plain old raw pointer, which is equivalent to true when the pointer isn'T NULL

Deprecated:

obsoleted by C++11 rvalue references

Definition at line 77 of file scoped-holder-transfer.hpp.

Public Types
typedef PAR::const_pointer	const_pointer
typedef PAR::const_reference	const_reference
typedef PAR::difference_type	difference_type
typedef PAR::pointer	pointer
typedef PAR::reference	reference
typedef PAR::size_type	size_type
typedef PAR::value_type	value_type

Public Member Functions
	Allocator_TransferNoncopyable (const _ThisType &allo)
	Allocator_TransferNoncopyable (const PAR &allo)
template<typename X >
	Allocator_TransferNoncopyable (const std::allocator< X > &)
pointer	address (reference r) const
const_pointer	address (const_reference cr) const
pointer	allocate (size_type n, const void *p=0)
void	construct (pointer p, const TY &ref)
void	deallocate (pointer p, size_type n)
void	destroy (pointer p)
size_type	max_size () const

Classes
struct	rebind

Private Types
typedef Allocator_TransferNoncopyable< TY, PAR >	_ThisType

Private Attributes
PAR	par_

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Class Documentation

lib::Allocator_TransferNoncopyable::rebind

struct lib::Allocator_TransferNoncopyable::rebind

Class Members
typedef Allocator_TransferNoncopyable < XX, PAR >	other

Collaboration diagram for Allocator_TransferNoncopyable< TY, PAR >::rebind< XX >:

Collaboration diagram for Allocator_TransferNoncopyable< TY, PAR >:

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

• scoped-holder-transfer.hpp