__gnu_cxx::bitmap_allocator< _Tp > Class Template Reference

Inheritance diagram for __gnu_cxx::bitmap_allocator< _Tp >:

Public Types
typedef free_list::__mutex_type	__mutex_type
typedef const _Tp *	const_pointer
typedef const _Tp &	const_reference
typedef ptrdiff_t	difference_type
typedef _Tp *	pointer
typedef std::true_type	propagate_on_container_move_assignment
typedef _Tp &	reference
typedef size_t	size_type
typedef _Tp	value_type

Public Member Functions
	bitmap_allocator (const bitmap_allocator &) noexcept
template<typename _Tp1 >
	bitmap_allocator (const bitmap_allocator< _Tp1 > &) noexcept
pointer	_M_allocate_single_object () throw (std::bad_alloc)
void	_M_deallocate_single_object (pointer __p) throw ()
pointer	address (reference __r) const noexcept
const_pointer	address (const_reference __r) const noexcept
pointer	allocate (size_type __n)
pointer	allocate (size_type __n, typename bitmap_allocator< void >::const_pointer)
template<typename _Up , typename... _Args>
void	construct (_Up *__p, _Args &&...__args)
void	deallocate (pointer __p, size_type __n) throw ()
template<typename _Up >
void	destroy (_Up *__p)
size_type	max_size () const noexcept

Private Types
typedef vector_type::iterator	iterator
typedef __detail::__mini_vector < value_type >	vector_type

Private Member Functions
void	_M_clear ()
size_t *	_M_get (size_t __sz) throw (std::bad_alloc)
void	_M_insert (size_t *__addr) throw ()

Detailed Description

template<typename _Tp>
class __gnu_cxx::bitmap_allocator< _Tp >

Bitmap Allocator, primary template.

Definition at line 59 of file ext/alloc_traits.h.

Member Function Documentation

template<typename _Tp >

pointer __gnu_cxx::bitmap_allocator< _Tp >::_M_allocate_single_object ( ) throw ( std::bad_alloc )

inline

Allocates memory for a single object of size sizeof(_Tp).

Exceptions

std::bad_alloc.

If memory can not be allocated.

Complexity: Worst case complexity is O(N), but that is hardly ever hit. If and when this particular case is encountered, the next few cases are guaranteed to have a worst case complexity of O(1)! That's why this function performs very well on average. You can consider this function to have a complexity referred to commonly as: Amortized Constant time.

Definition at line 827 of file bitmap_allocator.h.

References __gnu_cxx::__detail::__bit_allocate(), __gnu_cxx::__detail::__num_bitmaps(), and __gnu_cxx::_Bit_scan_forward().

template<typename _Tp >

void __gnu_cxx::bitmap_allocator< _Tp >::_M_deallocate_single_object ( pointer  __p ) throw ( )

inline

Deallocates memory that belongs to a single object of size sizeof(_Tp).

Complexity: O(lg(N)), but the worst case is not hit often! This is because containers usually deallocate memory close to each other and this case is handled in O(1) time by the deallocate function.

Definition at line 917 of file bitmap_allocator.h.

References __gnu_cxx::__detail::__bit_free(), __gnu_cxx::__detail::__num_bitmaps(), std::__rotate(), and __gnu_cxx::free_list::_M_insert().

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

• ext/alloc_traits.h
• bitmap_allocator.h