Rust中的對象和類

Question

我在擺弄Rust，試着做例子，試着做一個課。我一直在尋找的example of StatusLineText

它不斷提高的錯誤：

error: `self` is not available in a static method. Maybe a `self` argument is missing? [E0424] 
      self.id + self.extra 
      ^~~~ 

error: no method named `get_total` found for type `main::Thing` in the current scope 
    println!("the thing's total is {}", my_thing.get_total()); 
               ^~~~~~~~~ 

我的代碼是相當簡單：

fn main() { 
    struct Thing { 
     id: i8, 
     extra: i8, 
    } 

    impl Thing { 
     pub fn new() -> Thing { 
      Thing { id: 3, extra: 2 } 
     } 
     pub fn get_total() -> i8 { 
      self.id + self.extra 
     } 
    } 

    let my_thing = Thing::new(); 
    println!("the thing's total is {}", my_thing.get_total()); 
} 

Answer 1

您需要添加一個明確的self參數，使methods：

fn get_total(&self) -> i8 { 
    self.id + self.extra 
} 

沒有ex的函數暗self參數被認爲是associated functions，可以在沒有特定實例的情況下調用該參數。