fix time example

struct-patch/examples/time.rs

@@ -6,7 +6,10 @@ use struct_patch::Patch;
 #[patch(name = "FileConfig", attribute(derive(Deserialize, Debug)))]
 struct Config {
     #[serde(with = "humantime_serde")]
-    #[patch(attribute(serde(with = "humantime_serde")))]
+    #[patch(attribute(serde(with = "humantime_serde", default)))]
+    // NOTE:
+    // We need extra default parameter for Option<T>.
+    // https://github.com/jean-airoldie/humantime-serde/issues/13#issuecomment-2388437558
     time: Duration,
 }
 
@@ -21,14 +24,9 @@ fn main() {
     patched.apply(patch);
     assert_eq!(patched.time, Duration::from_millis(200));
 
-    // NOTE
-    // Following code does not work, because `humantime_serde` does not allow `Option<>` field
-    // anymore.
-    // https://github.com/jean-airoldie/humantime-serde/issues/13
-    //
-    // let empty_patch: FileConfig = toml::from_str("").unwrap();
+    let empty_patch: FileConfig = toml::from_str("").unwrap();
 
-    // let mut patched = config.clone();
-    // patched.apply(empty_patch);
-    // assert_eq!(patched.time, Duration::from_millis(500));
+    let mut patched = config.clone();
+    patched.apply(empty_patch);
+    assert_eq!(patched.time, Duration::from_millis(500));
 }