Rust语法之注释

     // Line comments are anything after ‘//’ and extend to the end of the line.

     let x = 5; // this is also a line comment.

     // If you have a long explanation for something, you can put line comments next
     // to each other. Put a space between the // and your comment so that it’s
     // more readable.

     /// Adds one to the number given.
     ///
     /// # Examples
     ///
     /// ```
     /// let five = 5;
     ///
     /// assert_eq!(6, add_one(5));
     /// ```
     fn add_one(x: i32) -> i32 {
         x + 1
     }