Lifetimes and References

Struct Reference

Holding a Borrowed Field

A struct can hold a reference when its lifetime parameter says the reference stays valid long enough.

Program

Play the program to borrow a label and repeat the borrowed text.

struct_reference.rs 
struct Label<'a> {
    text: &'a str,
}

fn main() {
    let word = "trace";
    let repeat = ;
    let label = Label { text: word };
    let output = label.text.repeat(repeat);
    println!("{output}");
}

struct Label<'a> {
    text: &'a str,
}

fn main() {
    let word = "trace";
    let repeat = ;
    let label = Label { text: word };
    let output = label.text.repeat(repeat);
    println!("{output}");
}

struct Label<'a> {
    text: &'a str,
}

fn main() {
    let word = "trace";
    let repeat = ;
    let label = Label { text: word };
    let output = label.text.repeat(repeat);
    println!("{output}");
}
lifetime on struct `Label<'a>` says the struct contains a reference valid for `'a`.
borrowed field `text: &'a str` stores a borrowed string slice.
method on borrow `label.text.repeat(repeat)` reads through the borrowed field.