fallback_allocator< Default, Fallback > Class Template Reference

Detailed Description

template<class Default, class Fallback>
class foonathan::memory::fallback_allocator< Default, Fallback >

A RawAllocator with a fallback.

Allocation first tries Default, if it fails, it uses Fallback.

Requires:

Default must be a composable RawAllocator, Fallback must be a RawAllocator.

Typedefs
using	default_allocator_type = typename allocator_traits< Default >::allocator_type
using	fallback_allocator_type = typename allocator_traits< Fallback >::allocator_type
using	is_stateful = std::integral_constant< bool, default_traits::is_stateful::value||fallback_traits::is_stateful::value >

Member Functions
	fallback_allocator ()
	fallback_allocator (default_allocator_type &&default_alloc, fallback_allocator_type &&fallback_alloc={})
void *	allocate_node (std::size_t size, std::size_t alignment)
void *	allocate_array (std::size_t count, std::size_t size, std::size_t alignment)
void	deallocate_node (void *ptr, std::size_t size, std::size_t alignment) noexcept
void	deallocate_array (void *ptr, std::size_t count, std::size_t size, std::size_t alignment) noexcept
void *	try_allocate_node (std::size_t size, std::size_t alignment) noexcept
void *	allocate_array (std::size_t count, std::size_t size, std::size_t alignment) noexcept
bool	try_deallocate_node (void *ptr, std::size_t size, std::size_t alignment) noexcept
bool	try_deallocate_array (void *ptr, std::size_t count, std::size_t size, std::size_t alignment) noexcept
std::size_t	max_node_size () const
std::size_t	max_array_size () const
std::size_t	max_alignment () const
default_allocator_type &	get_default_allocator () noexcept
const default_allocator_type &	get_default_allocator () const noexcept
fallback_allocator_type &	get_fallback_allocator () noexcept
const fallback_allocator_type &	get_fallback_allocator () const noexcept

Constructors

fallback_allocator() [1/2]

fallback_allocator

(

)

Effects:

Default constructs both allocators.

Notes:

This function only participates in overload resolution, if both allocators are not stateful.

fallback_allocator() [2/2]

fallback_allocator ( default_allocator_type &&  default_alloc, fallback_allocator_type &&  fallback_alloc = {}  )

explicit

Effects:

Constructs the allocator by passing in the two allocators it has.

Member Functions

allocate_node()

void * allocate_node	(	std::size_t	size,
		std::size_t	alignment
	)

Effects:

First calls the compositioning (de)allocation function on the default_allocator_type. If that fails, uses the non-compositioning function of the fallback_allocator_type.

allocate_array() [1/2]

void * allocate_array	(	std::size_t	count,
		std::size_t	size,
		std::size_t	alignment
	)

Effects:

First calls the compositioning (de)allocation function on the default_allocator_type. If that fails, uses the non-compositioning function of the fallback_allocator_type.

deallocate_node()

void deallocate_node ( void *  ptr, std::size_t  size, std::size_t  alignment  )

noexcept

Effects:

First calls the compositioning (de)allocation function on the default_allocator_type. If that fails, uses the non-compositioning function of the fallback_allocator_type.

deallocate_array()

void deallocate_array ( void *  ptr, std::size_t  count, std::size_t  size, std::size_t  alignment  )

noexcept

Effects:

First calls the compositioning (de)allocation function on the default_allocator_type. If that fails, uses the non-compositioning function of the fallback_allocator_type.

try_allocate_node()

void * try_allocate_node ( std::size_t  size, std::size_t  alignment  )

noexcept

Effects:

First calls the compositioning (de)allocation function on the default_allocator_type. If that fails, uses the compositioning function of the fallback_allocator_type.

Requires:

The fallback_allocator_type msut be composable.

allocate_array() [2/2]

void * allocate_array ( std::size_t  count, std::size_t  size, std::size_t  alignment  )

noexcept

Effects:

First calls the compositioning (de)allocation function on the default_allocator_type. If that fails, uses the compositioning function of the fallback_allocator_type.

Requires:

The fallback_allocator_type msut be composable.

try_deallocate_node()

bool try_deallocate_node ( void *  ptr, std::size_t  size, std::size_t  alignment  )

noexcept

Effects:

First calls the compositioning (de)allocation function on the default_allocator_type. If that fails, uses the compositioning function of the fallback_allocator_type.

Requires:

The fallback_allocator_type msut be composable.

try_deallocate_array()

bool try_deallocate_array ( void *  ptr, std::size_t  count, std::size_t  size, std::size_t  alignment  )

noexcept

Effects:

First calls the compositioning (de)allocation function on the default_allocator_type. If that fails, uses the compositioning function of the fallback_allocator_type.

Requires:

The fallback_allocator_type msut be composable.

max_node_size()

std::size_t max_node_size

(

)

const

Returns:

The maximum of the two values from both allocators.

max_array_size()

std::size_t max_array_size

(

)

const

Returns:

The maximum of the two values from both allocators.

max_alignment()

std::size_t max_alignment

(

)

const

Returns:

The maximum of the two values from both allocators.

get_default_allocator() [1/2]

default_allocator_type & get_default_allocator ( )

noexcept

Returns:

A (const) reference to the default allocator.

get_default_allocator() [2/2]

const default_allocator_type & get_default_allocator ( ) const

noexcept

Returns:

A (const) reference to the default allocator.

get_fallback_allocator() [1/2]

fallback_allocator_type & get_fallback_allocator ( )

noexcept

Returns:

A (const) reference to the fallback allocator.

get_fallback_allocator() [2/2]

const fallback_allocator_type & get_fallback_allocator ( ) const

noexcept

Returns:

A (const) reference to the fallback allocator.