alb::v_100::affix_allocator< Allocator, Prefix, Sufix > Class Template Reference

#include <affix_allocator.hpp>

Public Types
using	allocator = Allocator
using	prefix = Prefix
using	sufix = Sufix

Public Member Functions
	affix_allocator (const affix_allocator &)=delete
affix_allocator &	operator= (const affix_allocator &)=delete
	affix_allocator (affix_allocator &&x)=default
affix_allocator &	operator= (affix_allocator &&x)=default
constexpr Prefix *	outer_to_prefix (const block &b) const noexcept
constexpr Sufix *	outer_to_sufix (const block &b) const noexcept
block	allocate (size_t n) noexcept
void	deallocate (block &b) noexcept
template<typename U = Allocator>
std::enable_if < traits::has_owns< U >::value, bool >::type	owns (const block &b) const noexcept
bool	reallocate (block &b, size_t n) noexcept
template<typename U = Allocator>
std::enable_if < traits::has_expand< U > ::value, bool >::type	expand (block &b, size_t delta) noexcept

Static Public Member Functions
static constexpr size_t	good_size (size_t n)

Static Public Attributes
static constexpr bool	supports_truncated_deallocation = Allocator::supports_truncated_deallocation
static constexpr unsigned	alignment = Allocator::alignment
static constexpr size_t	prefix_size
static constexpr size_t	sufix_size

Detailed Description

template<class Allocator, typename Prefix, typename Sufix = affix_helper::no_affix>
class alb::v_100::affix_allocator< Allocator, Prefix, Sufix >

This allocator enables the possibility to surround allocated memory blocks with guards, ref-counter, mutex or etc. It is used by the alb::allocator_with_stats It automatically places an object of type Prefix before the returned memory location and an object of type Sufix after it. In case that they are of type affix_allocatorHelper::Empty nothing is inserted. Depending on the alignment of the used Allocator, Prefix, memory and Sufix are each aligned. Prefix and Sufix, if used, must be trivially copyable. (This cannot be statically asserted, because this would block the possibility to use this allocator as guard for memory under- or overflow. One should keep in mind, that using a Sufix is not CPU cache friendly!

Template Parameters

Allocator	The allocator that is used as underlying allocator
Prefix	If defined, then an object of that kind is constructed in front of any returned block
Sufix	If defined, then an object of that kind is constructed beyond any returned block

Definition at line 45 of file affix_allocator.hpp.

Member Function Documentation

template<class Allocator, typename Prefix, typename Sufix = affix_helper::no_affix>

block alb::v_100::affix_allocator< Allocator, Prefix, Sufix >::allocate ( size_t  n )

inlinenoexcept

Allocates a Block of n bytes. Actually a Block of n + sizeof(Prefix) + sizeof(Sufix) bytes is allocated. Depending of the defines Prefix and Sufix types objects of this gets instantiated before and/or beyond the returned Block. If Zero bytes are allocated then no allocation at all takes places and an empty Block is returned.

Parameters

n	Specifies the number of requested bytes. n or more bytes are returned, depending on the alignment of the underlying Allocator.

Definition at line 128 of file affix_allocator.hpp.

template<class Allocator, typename Prefix, typename Sufix = affix_helper::no_affix>

void alb::v_100::affix_allocator< Allocator, Prefix, Sufix >::deallocate ( block &  b )

inlinenoexcept

The given block gets deallocated. If Prefix or Sufix are defined then their d'tor(s) are called.

Parameters

b	The Block that should be freed.

Definition at line 154 of file affix_allocator.hpp.

template<class Allocator, typename Prefix, typename Sufix = affix_helper::no_affix>

template<typename U = Allocator>

std::enable_if<traits::has_expand<U>::value, bool>::type alb::v_100::affix_allocator< Allocator, Prefix, Sufix >::expand ( block &  b, size_t  delta  )

inlinenoexcept

The method tries to expand the given block by at least delta bytes insito at the given location. This is only available if the underlaying Allocator implements ::expand().

Parameters

b	The block that should be expanded
delta	The number of bytes that the given block should be increased

Returns

True, if the operation was successful.

Definition at line 220 of file affix_allocator.hpp.

template<class Allocator, typename Prefix, typename Sufix = affix_helper::no_affix>

constexpr Prefix* alb::v_100::affix_allocator< Allocator, Prefix, Sufix >::outer_to_prefix ( const block &  b ) const

inlinenoexcept

This Method returns on a given block the prefix.

Parameters

b	The block that was prefixed. The result is absolute unpredictable if a block is passed, that is not owned by this allocator!

Returns

Pointer to the Prefix before the given block

Definition at line 103 of file affix_allocator.hpp.

template<class Allocator, typename Prefix, typename Sufix = affix_helper::no_affix>

constexpr Sufix* alb::v_100::affix_allocator< Allocator, Prefix, Sufix >::outer_to_sufix ( const block &  b ) const

inlinenoexcept

This Method returns on a given block the sufix.

Parameters

b	The block that was sufixed. The result is absolute unpredictable if a block is passed, that is not owned by this allocator!

Returns

Pointer to the sufix before the given block

Definition at line 114 of file affix_allocator.hpp.

template<class Allocator, typename Prefix, typename Sufix = affix_helper::no_affix>

template<typename U = Allocator>

std::enable_if<traits::has_owns<U>::value, bool>::type alb::v_100::affix_allocator< Allocator, Prefix, Sufix >::owns ( const block &  b ) const

inlinenoexcept

If the underlying Allocator defines ::owns() this method is available. It returns true, if the given block is owned by this allocator.

Parameters

b	The Block that should be checked for ownership

Definition at line 177 of file affix_allocator.hpp.

template<class Allocator, typename Prefix, typename Sufix = affix_helper::no_affix>

bool alb::v_100::affix_allocator< Allocator, Prefix, Sufix >::reallocate ( block &  b, size_t  n  )

inlinenoexcept

The given block gets reallocated to the new provided size n. Any potential defined Prefix and/or Sufix gets copied to the new location.

Parameters

b	The block that should be resized
n	The new size (n = zero means a deallocation)

Returns

True if the operation was successful

Definition at line 190 of file affix_allocator.hpp.

Member Data Documentation

template<class Allocator, typename Prefix, typename Sufix = affix_helper::no_affix>

constexpr size_t alb::v_100::affix_allocator< Allocator, Prefix, Sufix >::prefix_size

static

Initial value:

=
        std::is_same<Prefix, affix_helper::no_affix>::value ? 0 : internal::round_to_alignment(alignment, sizeof(Prefix))

Definition at line 80 of file affix_allocator.hpp.

template<class Allocator, typename Prefix, typename Sufix = affix_helper::no_affix>

constexpr size_t alb::v_100::affix_allocator< Allocator, Prefix, Sufix >::sufix_size

static

Initial value:

=
        std::is_same<Sufix, affix_helper::no_affix>::value ? 0 : internal::round_to_alignment(alignment, sizeof(Sufix))

Definition at line 83 of file affix_allocator.hpp.

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

• alb/affix_allocator.hpp