traits1.rs#
// traits2.rs
//
// Your task is to implement the trait `AppendBar` for a vector of strings. To
// implement this trait, consider for a moment what it means to 'append "Bar"'
// to a vector of strings.
//
// No boiler plate code this time, you can do this!
//
// Execute `rustlings hint traits2` or use the `hint` watch subcommand for a hint.
trait AppendBar {
fn append_bar(self) -> Self;
}
impl AppendBar for Vec<String> {
fn append_bar(mut self) -> Self {
self.push(String::from("Bar"));
self
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn is_vec_pop_eq_bar() {
let mut foo = vec![String::from("Foo")].append_bar();
assert_eq!(foo.pop().unwrap(), String::from("Bar"));
assert_eq!(foo.pop().unwrap(), String::from("Foo"));
}
}
traits3.rs#
// traits3.rs
//
// Your task is to implement the Licensed trait for
// both structures and have them return the same
// information without writing the same function twice.
//
// Consider what you can add to the Licensed trait.
// Execute `rustlings hint traits3` or use the `hint` watch subcommand for a hint.
pub trait Licensed {
fn licensing_info(&self) -> String {
String::from("Some information")
}
}
struct SomeSoftware {
version_number: i32,
}
struct OtherSoftware {
version_number: String,
}
impl Licensed for SomeSoftware {} // Don't edit this line
impl Licensed for OtherSoftware {} // Don't edit this line
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn is_licensing_info_the_same() {
let licensing_info = String::from("Some information");
let some_software = SomeSoftware { version_number: 1 };
let other_software = OtherSoftware {
version_number: "v2.0.0".to_string(),
};
assert_eq!(some_software.licensing_info(), licensing_info);
assert_eq!(other_software.licensing_info(), licensing_info);
}
}
traits4.rs#
// traits4.rs
//
// Your task is to replace the '??' sections so the code compiles.
// Don't change any line other than the marked one.
// Execute `rustlings hint traits4` or use the `hint` watch subcommand for a hint.
pub trait Licensed {
fn licensing_info(&self) -> String {
"some information".to_string()
}
}
struct SomeSoftware {}
struct OtherSoftware {}
impl Licensed for SomeSoftware {}
impl Licensed for OtherSoftware {}
// YOU MAY ONLY CHANGE THE NEXT LINE
fn compare_license_types(software: impl Licensed, software_two: impl Licensed) -> bool {
software.licensing_info() == software_two.licensing_info()
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn compare_license_information() {
let some_software = SomeSoftware {};
let other_software = OtherSoftware {};
assert!(compare_license_types(some_software, other_software));
}
#[test]
fn compare_license_information_backwards() {
let some_software = SomeSoftware {};
let other_software = OtherSoftware {};
assert!(compare_license_types(other_software, some_software));
}
}
traits5.rs#
// traits5.rs
//
// Your task is to replace the '??' sections so the code compiles.
// Don't change any line other than the marked one.
// Execute `rustlings hint traits5` or use the `hint` watch subcommand for a hint.
pub trait SomeTrait {
fn some_function(&self) -> bool {
true
}
}
pub trait OtherTrait {
fn other_function(&self) -> bool {
true
}
}
struct SomeStruct {}
struct OtherStruct {}
impl SomeTrait for SomeStruct {}
impl OtherTrait for SomeStruct {}
impl SomeTrait for OtherStruct {}
impl OtherTrait for OtherStruct {}
// YOU MAY ONLY CHANGE THE NEXT LINE
fn some_func(item: impl SomeTrait + OtherTrait) -> bool {
item.some_function() && item.other_function()
}
fn main() {
some_func(SomeStruct {});
some_func(OtherStruct {});
}