Add package for determining integer sizes

integer/integer.go

@@ -0,0 +1,17 @@
+package integer
+
+func UnsignedMin(width int) uint64 {
+	return 0
+}
+
+func UnsignedMax(width int) uint64 {
+	return (1 << width) - 1
+}
+
+func SignedMin(width int) int64 {
+	return -1 - int64(UnsignedMax(width) / 2)
+}
+
+func SignedMax(width int) int64 {
+	return int64(UnsignedMax(width) / 2)
+}