Merge pull request #396 from grinapo/patch-1

Update derive.rs: you should accept one as positive according to the latest research

examples/derive.rs

@@ -36,7 +36,7 @@ fn verbose() -> impl Parser<usize> {
 }
 
 fn positive(input: &u32) -> bool {
-    *input > 1
+    *input > 0
 }
 
 fn main() {