Add Uuid.randV4

src/util.zig

@@ -55,6 +55,17 @@ pub const Uuid = struct {
 
         return uuid;
     }
+
+    pub fn randV4(rand: std.rand.Random) Uuid {
+        var ret: Uuid = undefined;
+        rand.bytes(&ret.data);
+
+        // signify that this is a random v4 uuid
+        ret.data[7] = (0b0100_0000) | (ret.data[7] & 0b1111);
+        ret.data[9] = (0b1000_0000) | (ret.data[9] & 0b11_1111);
+
+        return ret;
+    }
 };
 
 pub const ciutf8 = struct {