23 General utilities library [utilities]

23.12 Memory resources [mem.res]

23.12.2 Class memory_­resource [mem.res.class]

23.12.2.2 memory_­resource private virtual member functions [mem.res.private]

virtual void* do_allocate(size_t bytes, size_t alignment) = 0;
1
#
Requires: alignment shall be a power of two.
2
#
Returns: A derived class shall implement this function to return a pointer to allocated storage ([basic.stc.dynamic.deallocation]) with a size of at least bytes.
The returned storage is aligned to the specified alignment, if such alignment is supported ([basic.align]); otherwise it is aligned to max_­align.
3
#
Throws: A derived class implementation shall throw an appropriate exception if it is unable to allocate memory with the requested size and alignment.
virtual void do_deallocate(void* p, size_t bytes, size_t alignment) = 0;
4
#
Requires: p shall have been returned from a prior call to allocate(bytes, alignment) on a memory resource equal to *this, and the storage at p shall not yet have been deallocated.
5
#
Effects: A derived class shall implement this function to dispose of allocated storage.
6
#
Throws: Nothing.
virtual bool do_is_equal(const memory_resource& other) const noexcept = 0;
7
#
Returns: A derived class shall implement this function to return true if memory allocated from this can be deallocated from other and vice-versa, otherwise false.
[ Note
:
The most-derived type of other might not match the type of this.
For a derived class D, a typical implementation of this function will immediately return false if dynamic_­cast<const D*>(&other) == nullptr.
— end note
 ]