pub trait KeyValueDbTraitSingleWriter: KeyValueDbTraitOwnedRead {
    // Required methods
    fn delete(&mut self, key: &[u8]) -> Result<Option<Option<Self::ValueType>>>;
    fn put(
        &mut self,
        key: &[u8],
        value: &<Self::ValueType as DbValueType>::Type,
    ) -> Result<Option<Option<Self::ValueType>>>;
    // Provided methods
    fn delete_with_number_key(
        &mut self,
        key: i64,
    ) -> Result<Option<Option<Self::ValueType>>> { ... }
    fn put_with_number_key(
        &mut self,
        key: i64,
        value: &<Self::ValueType as DbValueType>::Type,
    ) -> Result<Option<Option<Self::ValueType>>> { ... }
}Required Methods§
Sourcefn delete(&mut self, key: &[u8]) -> Result<Option<Option<Self::ValueType>>>
 
fn delete(&mut self, key: &[u8]) -> Result<Option<Option<Self::ValueType>>>
Return Some(maybe_old_value) or None if the db don’t support reading the old value at deletion.