set flags to options
set preferredProps to options
set requiredProps to options
set type index mask to options
Initializes an AllocOptions with usage
Control flags
mask of memory type indices (0b0101 means indices 0 and 2) that, if not zero, will constrain MemoryRequirement.memTypeMask
MemProps bits that are optional but are preferred to be present. Allocation will favor memory types with these bits if available, but may fallback to other memory types.
MemProps bits that must be set. Allocation will fail if it can't allocate a memory type satisfies all bits.
Intended usage. Will affect preferredBits and requiredBits;
Structure controlling an allocation of memory