1 files changed, 24 insertions, 0 deletions
diff --git a/src/units.rs b/src/units.rs
index e4576bc..5128b6e 100644
--- a/src/units.rs
+++ b/src/units.rs
@@ -162,6 +162,30 @@ pub(crate) mod duration_option {
     }
 }
 
+/// Serde for an optional `Duration` in a request (JSON body or query string), read as
+/// [`duration_option`] reads it; absent is `None`. Use with `#[serde(default)]`.
+pub(crate) mod optional_duration {
+    use std::time::Duration;
+
+    use serde::{Deserializer, Serializer};
+
+    pub(crate) fn serialize<S: Serializer>(
+        value: &Option<Duration>,
+        s: S,
+    ) -> Result<S::Ok, S::Error> {
+        match value {
+            Some(duration) => super::duration_option::serialize(duration, s),
+            None => s.serialize_none(),
+        }
+    }
+
+    pub(crate) fn deserialize<'de, D: Deserializer<'de>>(
+        d: D,
+    ) -> Result<Option<Duration>, D::Error> {
+        super::duration_option::deserialize(d).map(Some)
+    }
+}
+
 /// Serde for a size option: a string as [`parse_size`] reads it, or a number of bytes;
 /// written as [`format_size`].
 pub(crate) mod size_option {