API Reference — `pma/resources/AlignedMemoryResource`

`AlignedMemoryResource : public MemoryResource`

Allocate and free memory blocks at a specific byte boundary. Use this when your data structures require alignment guarantees — for example, SIMD-optimized types — that the default allocator does not provide.

When to use this

Reach for AlignedMemoryResource when allocation must land on a specific byte boundary, such as 16-byte-aligned buffers for SSE operations or 64-byte boundaries for cache-line-sensitive data. Use the base MemoryResource when alignment is not a concern.

Example

pma::AlignedMemoryResource resource;

// Allocate 256 bytes aligned to a 16-byte boundary (e.g., for SSE data)
void* buffer = resource.allocate(256, 16);

// ... use buffer ...

// Deallocate — pass the same size and alignment used in allocate
resource.deallocate(buffer, 256, 16);

Parameters

allocate:

Name	Type	Description
`size`	`std::size_t`	required — number of bytes to allocate
`alignment`	`std::size_t`	required — required byte alignment of the returned pointer

deallocate:

Name	Type	Description
`ptr`	`void*`	required — pointer previously returned by `allocate`
`size`	`std::size_t`	required — must match the size passed to `allocate`
`alignment`	`std::size_t`	required — must match the alignment passed to `allocate`

Returns

void* — pointer to the allocated memory block, aligned to the requested boundary. Returned by allocate; deallocate returns nothing.

Watch out for

deallocate requires passing the same size and alignment values that were used in the corresponding allocate call. Mismatched values are undefined behavior — track these at the call site.

Relationships

MemoryResource — base class; AlignedMemoryResource extends it to honor alignment contracts

API Reference — pma/resources/AlignedMemoryResource

AlignedMemoryResource : public MemoryResource