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Example of using traits with structs
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| trait HasAStringInIt { | |
| fn get_str(&self) -> &str; | |
| fn set_str(&mut self, new_string: String); | |
| } | |
| struct File { | |
| name: String, | |
| contents: Vec<u8>, | |
| } | |
| impl HasAStringInIt for File { | |
| fn get_str(&self) -> &str { | |
| &self.name | |
| } | |
| fn set_str(&mut self, new_string: String) { | |
| self.name = new_string; | |
| } | |
| } | |
| struct Message { | |
| from: User, | |
| contents: String, | |
| } | |
| impl HasAStringInIt for Message { | |
| fn get_str(&self) -> &str { | |
| &self.contents | |
| } | |
| fn set_str(&mut self, new_string: String) { | |
| self.contents = new_string; | |
| } | |
| } | |
| struct User { | |
| username: String, | |
| } | |
| impl HasAStringInIt for User { | |
| fn get_str(&self) -> &str { | |
| &self.username | |
| } | |
| fn set_str(&mut self, new_string: String) { | |
| self.username = new_string; | |
| } | |
| } | |
| struct Person { | |
| name: String, | |
| age: u32, | |
| } | |
| impl HasAStringInIt for Person { | |
| fn get_str(&self) -> &str { | |
| &self.name | |
| } | |
| fn set_str(&mut self, new_string: String) { | |
| self.name = new_string; | |
| } | |
| } | |
| fn print_has_a_string_in_it<T>(has_a_string_in_it: &T) | |
| where | |
| T: HasAStringInIt, | |
| { | |
| println!("There is a string here: {}", has_a_string_in_it.get_str()); | |
| } | |
| fn main() { | |
| let file = File { | |
| name: "Woah".into(), | |
| contents: Vec::new(), | |
| }; | |
| let message = Message { | |
| from: User { username: "jingle.dog".into() }, | |
| contents: "Blep".into(), | |
| }; | |
| let user = User { username: "asonix".into() }; | |
| let person = Person { | |
| name: "Arlo".into(), | |
| age: 20, | |
| }; | |
| print_has_a_string_in_it(&file); | |
| print_has_a_string_in_it(&message); | |
| print_has_a_string_in_it(&user); | |
| print_has_a_string_in_it(&person); | |
| // make file mutable so we can change it | |
| let mut file = file; | |
| file.set_str("I gave this file a new name".into()); | |
| print_has_a_string_in_it(&file); | |
| } |
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