This protocol provides a pure abstract interface and contract for clients and suppliers of raw aligned memory. If the requested memory cannot be returned, the contract requires that an std::bad_alloc exception be thrown.

Synopsis

Declared in <bdlma_alignedallocator.h>

class AlignedAllocator
    : public bslma::Allocator

Base Classes

Name

Description

bslma::Allocator

This protocol class provides a pure abstract interface and contract for clients and suppliers of raw memory. If the requested memory cannot be returned, the contract requires that an std::bad_alloc exception be thrown. Note that memory is guaranteed to be sufficiently aligned for any object of the requested size on the current platform, which may be less than the maximal alignment guarantee afforded by global operator new.

Type Aliases

Name

Description

size_type

Alias for an unsigned integral type capable of representing the number of bytes in this platform's virtual address space.

Member Functions

Name

Description

operator=

allocate

Return a newly allocated block of memory of the specified size bytes.

allocateAligned [virtual]

Return the address of a newly allocated block of memory of at least the specified positive size (in bytes), sufficiently aligned such that the returned address satisfies, for the specified alignment, 0 == (address & (alignment ‐ 1)). If size is 0, a null pointer is returned with no other effect. If the requested number of appropriately aligned bytes cannot be returned, then a bsl::bad_alloc exception is thrown, or in a non‐exception build the program is terminated. The behavior is undefined unless alignment is both a multiple of sizeof(void *) and an integral non‐negative power of two.

deallocate

Return the memory block at the specified address to this allocator.

deleteObject

deleteObject overloads

deleteObjectRaw

deleteObjectRaw overloads

is_equal

Static Member Functions

Name

Description

throwBadAlloc

Throw std::bad_alloc if exceptions are enabled or abort the program otherwise. Derived classes and helper functions will typically call this function when they are unable to satisfy an allocation request. This function never returns.

Protected Member Functions

Name

Description

do_allocate [virtual]

Return a newly allocated block of memory of (at least) the specified positive bytes and having at least the specified alignment. Unless overriden in a derived class, the return value is this‐>allocate(bytes). If this allocator cannot return the requested number of bytes or cannot satisfy the alignment request, then it will throw a std::bad_alloc exception in an exception‐enabled build, or else will abort the program in a non‐exception build. Unless overriden in a derived class, this function will forward the allocation request to the allocate virtual function, padding bytes and adjusting the return value as necessary to ensure sufficient alignment. Note that if bytes is 0, the same non‐null value will be returned every time.

do_deallocate [virtual]

Return the memory block at the specified p address, having the specified bytes and specified alignment, back to this allocator. Unless overriden in a derived class, this function will forward the deallocation request to the deallocate virtual function, padding bytes and adjusting p as necessary to account for alignment values other than the natural alignment for an object of size bytes. The behavior is undefined unless address is a block allocated from this allocator object using the same bytes and alignment and not already deallocated.

do_is_equal [virtual]

Return true if this allocator is equal to the specified other allocator, meaning (at least) that a memory block allocated by one can be deallocated by the other; otherwise return false. Unless overriden, this method returns this == &other.

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