Lifetimes in Struct Definitions

Snippet

Lifetimes in Struct Definitions

Lifetimes ensure references in structs don't outlive the data they reference. The struct holds a reference with lifetime 'a, which must be at least as long as the struct instance itself. This prevents dangling references at compile time.

snippet.rs
rust
struct Excerpt<'a> {
    part: &'a str,
}
 
fn main() {
    let text = String::from("Hello world");
    let excerpt = Excerpt { part: &text[6..11] };
    println!("Excerpt: {}", excerpt.part);
}

Breakdown

struct Excerpt<'a> {

Struct definition with lifetime parameter 'a

part: &'a str,

Reference to str that must live at least as long as 'a

let excerpt = Excerpt { part: &text[6..11] };

Creates instance - excerpt borrows from text, lifetimes are connected

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Lifetimes in Struct Definitions

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