public AlignedMemoryAlloc(int size, int alignment)
{
// Make sure the alignment is positive and a power of two.
if (alignment <= 0 || alignment.CountBits() != 1)
{
throw new ArgumentOutOfRangeException("alignment");
}
// Since we are going to align our pointer, we need to account for
// any padding at the beginning.
_realMemory = PrivateHeap.Allocate(size + alignment - 1);
// aligned memory = (memory + alignment - 1) & ~(alignment - 1)
this.Memory = _realMemory.Align(alignment);
this.Size = size;
}