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Diffstat (limited to 'rustlings/exercises/16_lifetimes')
| -rw-r--r-- | rustlings/exercises/16_lifetimes/README.md | 22 | ||||
| -rw-r--r-- | rustlings/exercises/16_lifetimes/lifetimes1.rs | 28 | ||||
| -rw-r--r-- | rustlings/exercises/16_lifetimes/lifetimes2.rs | 20 | ||||
| -rw-r--r-- | rustlings/exercises/16_lifetimes/lifetimes3.rs | 16 |
4 files changed, 0 insertions, 86 deletions
diff --git a/rustlings/exercises/16_lifetimes/README.md b/rustlings/exercises/16_lifetimes/README.md deleted file mode 100644 index 91373f7..0000000 --- a/rustlings/exercises/16_lifetimes/README.md +++ /dev/null @@ -1,22 +0,0 @@ -# Lifetimes - -Lifetimes tell the compiler how to check whether references live long -enough to be valid in any given situation. For example lifetimes say -"make sure parameter 'a' lives as long as parameter 'b' so that the return -value is valid". - -They are only necessary on borrows, i.e. references, -since copied parameters or moves are owned in their scope and cannot -be referenced outside. Lifetimes mean that calling code of e.g. functions -can be checked to make sure their arguments are valid. Lifetimes are -restrictive of their callers. - -If you'd like to learn more about lifetime annotations, the -[lifetimekata](https://tfpk.github.io/lifetimekata/) project -has a similar style of exercises to Rustlings, but is all about -learning to write lifetime annotations. - -## Further information - -- [Lifetimes (in Rust By Example)](https://doc.rust-lang.org/stable/rust-by-example/scope/lifetime.html) -- [Validating References with Lifetimes](https://doc.rust-lang.org/book/ch10-03-lifetime-syntax.html) diff --git a/rustlings/exercises/16_lifetimes/lifetimes1.rs b/rustlings/exercises/16_lifetimes/lifetimes1.rs deleted file mode 100644 index 683bd75..0000000 --- a/rustlings/exercises/16_lifetimes/lifetimes1.rs +++ /dev/null @@ -1,28 +0,0 @@ -// The Rust compiler needs to know how to check whether supplied references are -// valid, so that it can let the programmer know if a reference is at risk of -// going out of scope before it is used. Remember, references are borrows and do -// not own their own data. What if their owner goes out of scope? - -// TODO: Fix the compiler error by updating the function signature. -fn longest<'a>(x: &'a str, y: &'a str) -> &'a str { - if x.len() > y.len() { - x - } else { - y - } -} - -fn main() { - // You can optionally experiment here. -} - -#[cfg(test)] -mod tests { - use super::*; - - #[test] - fn test_longest() { - assert_eq!(longest("abcd", "123"), "abcd"); - assert_eq!(longest("abc", "1234"), "1234"); - } -} diff --git a/rustlings/exercises/16_lifetimes/lifetimes2.rs b/rustlings/exercises/16_lifetimes/lifetimes2.rs deleted file mode 100644 index ebbc99c..0000000 --- a/rustlings/exercises/16_lifetimes/lifetimes2.rs +++ /dev/null @@ -1,20 +0,0 @@ -// Don't change this function. -fn longest<'a>(x: &'a str, y: &'a str) -> &'a str { - if x.len() > y.len() { - x - } else { - y - } -} - -fn main() { - // TODO: Fix the compiler error by moving one line. - - let string1 = String::from("long string is long"); - let string2 = String::from("xyz"); - let result; - { - result = longest(&string1, &string2); - } - println!("The longest string is '{result}'"); -} diff --git a/rustlings/exercises/16_lifetimes/lifetimes3.rs b/rustlings/exercises/16_lifetimes/lifetimes3.rs deleted file mode 100644 index 91e3922..0000000 --- a/rustlings/exercises/16_lifetimes/lifetimes3.rs +++ /dev/null @@ -1,16 +0,0 @@ -// Lifetimes are also needed when structs hold references. - -// TODO: Fix the compiler errors about the struct. -struct Book<'a> { - author: &'a str, - title: &'a str, -} - -fn main() { - let book = Book { - author: "George Orwell", - title: "1984", - }; - - println!("{} by {}", book.title, book.author); -} |