rand: rand_r(seed)

vlib/rand/rand.v

@@ -12,4 +12,18 @@ pub fn next(max int) int {
 	return C.rand() % max
 }
 
-fn C.rand() int 
+fn C.rand() int
+
+/**
+ * rand_r - reentrant pseudo-random number generator
+ *
+ * @param seed byref reentrant seed, holding current state
+ *
+ * @return a value between 0 and C.RAND_MAX (inclusive)
+ */
+pub fn rand_r(seed &int) int {
+	mut rs := seed
+	ns := ( *rs * 1103515245 + 12345 )
+	*rs = ns
+	return ns & 0x7fffffff
+}