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__gnu_cxx::bitmap_allocator(3) Library Functions Manual __gnu_cxx::bitmap_allocator(3)

NAME

__gnu_cxx::bitmap_allocator -

Bitmap Allocator, primary template.

SYNOPSIS

Inherits __gnu_cxx::free_list.

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 _Tp & reference
typedef size_t size_type
typedef _Tp value_type

Public Member Functions


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

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 710 of file bitmap_allocator.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 846 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 944 of file bitmap_allocator.h.

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

Author

Generated automatically by Doxygen for libstdc++ from the source code.

19 Jun 2018 libstdc++