Clippy2: exercises/clippy/clippy2.rs

题目

rust

// clippy2.rs
// 
// Execute `rustlings hint clippy2` or use the `hint` watch subcommand for a
// hint.

// I AM NOT DONE

fn main() {
    let mut res = 42;
    let option = Some(12);
    for x in option {
        res += x;
    }
    println!("{}", res);
}

题目解析

错误信息如下：

txt

⚠️  Compiling of exercises/clippy/clippy2.rs failed! Please try again. Here's the output:
    Checking clippy2 v0.0.1 (/home/jeffery/dev/rust/rustlings/exercises/clippy)
error: for loop over an `Option`. This is more readably written as an `if let` statement
  --> clippy2.rs:11:14
   |
11 |     for x in option {
   |              ^^^^^^
   |
   = note: `-D for-loops-over-fallibles` implied by `-D warnings`
help: to check pattern in a loop use `while let`
   |
11 |     while let Some(x) = option {
   |     ~~~~~~~~~~~~~~~ ~~~
help: consider using `if let` to clear intent
   |
11 |     if let Some(x) = option {
   |     ~~~~~~~~~~~~ ~~~

error: could not compile `clippy2` (bin "clippy2") due to previous error

信息提示我们，其实可以用while let或者if let来实现。

rust

fn main() {
    let mut res = 42;
    let option = Some(12);
    for x in option { 
    while let Some(x) = option { 
        res += x;
    }
    println!("{}", res);
}

或者

rust

fn main() {
    let mut res = 42;
    let option = Some(12);
    for x in option { 
    if let Some(x) = option { 
        res += x;
    }
    println!("{}", res);
}

Clippy2: exercises/clippy/clippy2.rs ​

题目 ​

题目解析 ​

Clippy2: exercises/clippy/clippy2.rs

题目

题目解析