From f23a4fe4bcb7ae0b47d625f89abb281646ea33a7 Mon Sep 17 00:00:00 2001 From: Jordan Gong Date: Thu, 3 Sep 2020 15:26:30 +0800 Subject: Care about lifetimes --- lifetimes/src/main.rs | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 lifetimes/src/main.rs (limited to 'lifetimes/src') diff --git a/lifetimes/src/main.rs b/lifetimes/src/main.rs new file mode 100644 index 0000000..8dec31f --- /dev/null +++ b/lifetimes/src/main.rs @@ -0,0 +1,41 @@ +fn longest<'a>(x: &'a str, y: &'a str) -> &'a str { + if x.len() > y.len() { + x + } else { + y + } +} + +use std::fmt::Display; + +// generic type params, trait bound, and lifetimes +fn longest_with_an_announcement<'a, T>( + x: &'a str, + y: &'a str, + ann: T, +) -> &'a str +where + T: Display, +{ + println!("Announcement! {}", ann); + if x.len() > y.len() { + x + } else { + y + } +} + +fn main() { + let string1 = String::from("abcd"); + let string2 = "xyz"; + + let result = longest(string1.as_str(), string2); + println!("The longest string is {}", result); + + let result = longest_with_an_announcement( + string1.as_str(), + string2, + "Today is someone's birthday!", + ); + println!("The longest string is {}", result); +} -- cgit v1.2.3