libstdc++
__gnu_cxx::bitmap_allocator< typename > Class Template Reference
Inheritance diagram for __gnu_cxx::bitmap_allocator< typename >:
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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>
class __gnu_cxx::bitmap_allocator< typename >

Bitmap Allocator, primary template.

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

Member Function Documentation

template<typename >
pointer __gnu_cxx::bitmap_allocator< typename >::_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 >
void __gnu_cxx::bitmap_allocator< typename >::_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().


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