阿索 将向量视为。 例子 use assoc :: AssocExt; let mut map = vec! [( "a" , 1 ), ( "b" , 2 )]; map. entry ( "c" ). or_insert ( 3 ); assert_eq! (map. get ( & "c" ), Some ( & 3 )); assert_eq! (map. entry ( "c" ). or_insert ( 4 ), & 3 );