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1832aba31e
Motivation ---------- I'm currently doing the rustlings course. I was pretty lost at quiz3 because I did not understand the problem. With this change I would have understood that it should be possible to use both `f32` or `&str` for the grade. I also googled quiz3 and found that other people got confused and used enums: https://www.reddit.com/r/learnrust/comments/wccx7s/rustlings_blocked_on_quiz3/ <details> <summary>My solution, hopefully I got it now</summary> ``` // quiz3.rs // // This quiz tests: // - Generics // - Traits // // An imaginary magical school has a new report card generation system written // in Rust! Currently the system only supports creating report cards where the // student's grade is represented numerically (e.g. 1.0 -> 5.5). However, the // school also issues alphabetical grades (A+ -> F-) and needs to be able to // print both types of report card! // // Make the necessary code changes in the struct ReportCard and the impl block // to support alphabetical report cards. Change the Grade in the second test to // "A+" to show that your changes allow alphabetical grades. // // Execute `rustlings hint quiz3` or use the `hint` watch subcommand for a hint. // I AM NOT DONE use std::fmt::Display; pub struct ReportCard<T: Display> { pub grade: T, pub student_name: String, pub student_age: u8, } impl <T: Display> ReportCard<T> { pub fn print(&self) -> String { format!("{} ({}) - achieved a grade of {}", &self.student_name, &self.student_age, &self.grade) } } mod tests { use super::*; #[test] fn generate_numeric_report_card() { let report_card = ReportCard { grade: 2.1, student_name: "Tom Wriggle".to_string(), student_age: 12, }; assert_eq!( report_card.print(), "Tom Wriggle (12) - achieved a grade of 2.1" ); } #[test] fn generate_alphabetic_report_card() { // TODO: Make sure to change the grade here after you finish the exercise. let report_card = ReportCard { grade: "A+", student_name: "Gary Plotter".to_string(), student_age: 11, }; assert_eq!( report_card.print(), "Gary Plotter (11) - achieved a grade of A+" ); } } ``` </details>
Exercise to Book Chapter mapping
| Exercise | Book Chapter |
|---|---|
| variables | §3.1 |
| functions | §3.3 |
| if | §3.5 |
| primitive_types | §3.2, §4.3 |
| vecs | §8.1 |
| move_semantics | §4.1-2 |
| structs | §5.1, §5.3 |
| enums | §6, §18.3 |
| strings | §8.2 |
| modules | §7 |
| hashmaps | §8.3 |
| options | §10.1 |
| error_handling | §9 |
| generics | §10 |
| traits | §10.2 |
| tests | §11.1 |
| lifetimes | §10.3 |
| iterators | §13.2-4 |
| threads | §16.1-3 |
| smart_pointers | §15, §16.3 |
| macros | §19.6 |
| clippy | §21.4 |
| conversions | n/a |