diff options
Diffstat (limited to 'solutions/14_generics')
| -rw-r--r-- | solutions/14_generics/generics1.rs | 17 | ||||
| -rw-r--r-- | solutions/14_generics/generics2.rs | 28 |
2 files changed, 45 insertions, 0 deletions
diff --git a/solutions/14_generics/generics1.rs b/solutions/14_generics/generics1.rs new file mode 100644 index 0000000..e2195fd --- /dev/null +++ b/solutions/14_generics/generics1.rs @@ -0,0 +1,17 @@ +// `Vec<T>` is generic over the type `T`. In most cases, the compiler is able to +// infer `T`, for example after pushing a value with a concrete type to the vector. +// But in this exercise, the compiler needs some help through a type annotation. + +fn main() { + // `u8` and `i8` can both be converted to `i16`. + let mut numbers: Vec<i16> = Vec::new(); + // ^^^^^^^^^^ added + + // Don't change the lines below. + let n1: u8 = 42; + numbers.push(n1.into()); + let n2: i8 = -1; + numbers.push(n2.into()); + + println!("{numbers:?}"); +} diff --git a/solutions/14_generics/generics2.rs b/solutions/14_generics/generics2.rs new file mode 100644 index 0000000..14f3f7a --- /dev/null +++ b/solutions/14_generics/generics2.rs @@ -0,0 +1,28 @@ +struct Wrapper<T> { + value: T, +} + +impl<T> Wrapper<T> { + fn new(value: T) -> Self { + Wrapper { value } + } +} + +fn main() { + // You can optionally experiment here. +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn store_u32_in_wrapper() { + assert_eq!(Wrapper::new(42).value, 42); + } + + #[test] + fn store_str_in_wrapper() { + assert_eq!(Wrapper::new("Foo").value, "Foo"); + } +} |
