Function sdb::btree::get

pub fn get<T, K, V, P>(
    txn: &'a T, 
    db: &Db_<K, V, P>, 
    k: &K, 
    v: Option<&V>
) -> Result<Option<(&'a K, &'a V)>, <T as LoadPage>::Error> where
    K: Storable + ?Sized,
    V: Storable + ?Sized,
    T: LoadPage,
    P: BTreePage<K, V>, 

Get the first entry of a database greater than or equal to k (or to (k, v) if v.is_some()).