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Diffstat (limited to 'exercises/15_traits')
| -rw-r--r-- | exercises/15_traits/README.md | 19 | ||||
| -rw-r--r-- | exercises/15_traits/traits1.rs | 42 | ||||
| -rw-r--r-- | exercises/15_traits/traits2.rs | 29 | ||||
| -rw-r--r-- | exercises/15_traits/traits3.rs | 42 | ||||
| -rw-r--r-- | exercises/15_traits/traits4.rs | 49 | ||||
| -rw-r--r-- | exercises/15_traits/traits5.rs | 40 |
6 files changed, 221 insertions, 0 deletions
diff --git a/exercises/15_traits/README.md b/exercises/15_traits/README.md new file mode 100644 index 0000000..ac87c64 --- /dev/null +++ b/exercises/15_traits/README.md @@ -0,0 +1,19 @@ +# Traits + +A trait is a collection of methods. + +Data types can implement traits. To do so, the methods making up the trait are defined for the data type. For example, the `String` data type implements the `From<&str>` trait. This allows a user to write `String::from("hello")`. + +In this way, traits are somewhat similar to Java interfaces and C++ abstract classes. + +Some additional common Rust traits include: + +- `Clone` (the `clone` method) +- `Display` (which allows formatted display via `{}`) +- `Debug` (which allows formatted display via `{:?}`) + +Because traits indicate shared behavior between data types, they are useful when writing generics. + +## Further information + +- [Traits](https://doc.rust-lang.org/book/ch10-02-traits.html) diff --git a/exercises/15_traits/traits1.rs b/exercises/15_traits/traits1.rs new file mode 100644 index 0000000..37dfcbf --- /dev/null +++ b/exercises/15_traits/traits1.rs @@ -0,0 +1,42 @@ +// traits1.rs +// +// Time to implement some traits! Your task is to implement the trait +// `AppendBar` for the type `String`. The trait AppendBar has only one function, +// which appends "Bar" to any object implementing this trait. +// +// Execute `rustlings hint traits1` or use the `hint` watch subcommand for a +// hint. + +// I AM NOT DONE + +trait AppendBar { + fn append_bar(self) -> Self; +} + +impl AppendBar for String { + // TODO: Implement `AppendBar` for type `String`. +} + +fn main() { + let s = String::from("Foo"); + let s = s.append_bar(); + println!("s: {}", s); +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn is_foo_bar() { + assert_eq!(String::from("Foo").append_bar(), String::from("FooBar")); + } + + #[test] + fn is_bar_bar() { + assert_eq!( + String::from("").append_bar().append_bar(), + String::from("BarBar") + ); + } +} diff --git a/exercises/15_traits/traits2.rs b/exercises/15_traits/traits2.rs new file mode 100644 index 0000000..3e35f8e --- /dev/null +++ b/exercises/15_traits/traits2.rs @@ -0,0 +1,29 @@ +// 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. + +// I AM NOT DONE + +trait AppendBar { + fn append_bar(self) -> Self; +} + +// TODO: Implement trait `AppendBar` for a vector of strings. + +#[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")); + } +} diff --git a/exercises/15_traits/traits3.rs b/exercises/15_traits/traits3.rs new file mode 100644 index 0000000..4e2b06b --- /dev/null +++ b/exercises/15_traits/traits3.rs @@ -0,0 +1,42 @@ +// 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. + +// I AM NOT DONE + +pub trait Licensed { + fn licensing_info(&self) -> String; +} + +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); + } +} diff --git a/exercises/15_traits/traits4.rs b/exercises/15_traits/traits4.rs new file mode 100644 index 0000000..4bda3e5 --- /dev/null +++ b/exercises/15_traits/traits4.rs @@ -0,0 +1,49 @@ +// 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. + +// I AM NOT DONE + +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: ??, software_two: ??) -> 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)); + } +} diff --git a/exercises/15_traits/traits5.rs b/exercises/15_traits/traits5.rs new file mode 100644 index 0000000..df18380 --- /dev/null +++ b/exercises/15_traits/traits5.rs @@ -0,0 +1,40 @@ +// 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. + +// I AM NOT DONE + +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: ??) -> bool { + item.some_function() && item.other_function() +} + +fn main() { + some_func(SomeStruct {}); + some_func(OtherStruct {}); +} |
