// 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. pub trait Grade { fn to_string(&self) -> String; } pub struct StrGrade(String); pub struct NumGrade(f32); impl Grade for StrGrade { fn to_string(&self) -> String { self.0.to_string() } } impl Grade for NumGrade { fn to_string(&self) -> String { self.0.to_string() } } pub struct ReportCard { pub grade: G, pub student_name: String, pub student_age: u8, } impl ReportCard { pub fn print(&self) -> String { format!( "{} ({}) - achieved a grade of {}", &self.student_name, &self.student_age, &self.grade.to_string() ) } } #[cfg(test)] mod tests { use super::*; #[test] fn generate_numeric_report_card() { let report_card = ReportCard { grade: NumGrade(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: StrGrade(String::from("A+")), student_name: "Gary Plotter".to_string(), student_age: 11, }; assert_eq!( report_card.print(), "Gary Plotter (11) - achieved a grade of A+" ); } }