Function deserialize_optional 

pub fn deserialize_optional<'de, D: Deserializer<'de>>(
    deserializer: D,
) -> Result<Option<Decimal>, D::Error>

Deserializes an optional exact decimal, accepting null as None.

Add #[serde(default)] to accept a missing field. Other values follow deserialize.

Errors

Returns an error if deserialize rejects a non-null value.