bdlb_nullableallocatedvalue_pointerbitspair

Functions
	bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::NullableAllocatedValue_PointerBitsPair ()
	bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::NullableAllocatedValue_PointerBitsPair (t_TYPE *ptr, unsigned flags=0)
bool	bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::equal (const NullableAllocatedValue_PointerBitsPair &other) const
t_TYPE *	bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::getPointer () const
	Return the held pointer.
bool	bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::readFlag (unsigned idx) const
void	bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::clearFlag (unsigned idx)
void	bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::setFlag (unsigned idx)
void	bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::setPointer (t_TYPE *new_ptr)
	Set the held pointer to the value of the specified new_ptr.
void	bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::swap (NullableAllocatedValue_PointerBitsPair &other)

Detailed Description

Outline

• Purpose
• Classes
• Description

Purpose

Provide a mechanism for using the unused bits of a pointer.

Classes

• bdlb::NullableAllocatedValue_PointerBitsPair: pointer and bits together.

See also

bdlb_nullablesllocatedvalue

Description

This private, subordinate component to bdlb_nullableallocatedvalue provides a templated class, bdlb::NullableAllocatedValue_PointerBitsPair, that allows access to the otherwise unused bits in a pointer to an object. The bdlb::NullableAllocatedValue class template uses bdlb::NullableAllocatedValue_PointerBitsPair to store some state about the object in the pointer to allocator field, saving 4 to 8 bytes (depending on the platform) for each instantiation.

bldb::NullableAllocatedValue_PointerBitsPair is a non-allocator-aware, value-semantic type.

Function Documentation

clearFlag()

template<class t_TYPE , unsigned t_NUM_BITS>

void bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::clearFlag ( unsigned  idx )

inline

Clear the flag specified by idx. The behavior is undefined unless idx < t_NUM_BITS.

equal()

template<class t_TYPE , unsigned t_NUM_BITS>

bool bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::equal ( const NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS > &  other ) const

inline

Return true if this object and the specified other have the same value, and false otherwise. Two NullableAllocatedValue_PointerBitsPair objects have the same value when their pointer and flags are the same.

getPointer()

template<class t_TYPE , unsigned t_NUM_BITS>

t_TYPE * bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::getPointer ( ) const

inline

NullableAllocatedValue_PointerBitsPair() [1/2]

template<class t_TYPE , unsigned t_NUM_BITS>

bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::NullableAllocatedValue_PointerBitsPair ( )

inline

Construct an object holding a null pointer value and all flags set to false.

NullableAllocatedValue_PointerBitsPair() [2/2]

template<class t_TYPE , unsigned t_NUM_BITS>

bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::NullableAllocatedValue_PointerBitsPair ( t_TYPE *  ptr, unsigned  flags = 0  )

inlineexplicit

Construct an object holding the specified ptr and optionally specified flags. The behavior is undefined unless flags <= k_Mask.

readFlag()

template<class t_TYPE , unsigned t_NUM_BITS>

bool bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::readFlag ( unsigned  idx ) const

inline

Return the value of the flag specified by idx. The behavior is undefined unless idx < t_NUM_BITS.

setFlag()

template<class t_TYPE , unsigned t_NUM_BITS>

void bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::setFlag ( unsigned  idx )

inline

Set the flag specified by idx. The behavior is undefined unless idx < t_NUM_BITS.

setPointer()

template<class t_TYPE , unsigned t_NUM_BITS>

void bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::setPointer ( t_TYPE *  new_ptr )

inline

swap()

template<class t_TYPE , unsigned t_NUM_BITS>

void bdlb::NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS >::swap ( NullableAllocatedValue_PointerBitsPair< t_TYPE, t_NUM_BITS > &  other )

inline

Efficiently exchange the value of this object with the value of the specified other object. This method provides the no-throw exception-safety guarantee.