键 值 雪橇- 从这里到这里都是下坡路！！！ 嵌入式数据库。 let tree = sled :: open ( "/tmp/welcome-to-sled" )?; // insert and get, similar to std's BTreeMap let old_value = tree. insert ( "key" , "value" )?; assert_eq! ( tree. get ( & "key" )?, Some (sled :: IVec :: from