return false // Negative values are never okay
		case cur.Offset > math.MaxInt64-cur.Length:
			return false // Integer overflow with large length
		case cur.endOffset() > size:
			return false // Region extends beyond the actual size
		case pre.endOffset() > cur.Offset:
			return false // Regions cannot overlap and must be in order
		}
		pre = cur
	}
	return true
}