This should be the full system path to the location of the Smarty class files. If this is not defined, then Smarty will attempt to determine the appropriate value automatically. If defined, the path must end with a slash.
此變數的值是 Smarty 類別檔（class file）的完整系統路徑，如果沒有定義的話 ，則 Smarty 會自己試著決定適當的值。如果有設定的話，則路徑最後必須包含斜線。