19 lines
715 B
Rust
19 lines
715 B
Rust
// https://google.github.io/comprehensive-rust/ownership/lifetimes-function-calls.html
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#[derive(Debug)]
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struct Point(i32, i32);
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// 'a is a generic parameter, it is inferred by the compiler.
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// Lifetimes start with ' and 'a is a typical default name.
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// Read &'a Point as “a borrowed Point which is valid for at least the lifetime a”.
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// The at least part is important when parameters are in different scopes.
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fn left_most<'a>(p1: &'a Point, p2: &'a Point) -> &'a Point {
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if p1.0 < p2.0 { p1 } else { p2 }
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}
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fn main() {
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let p1: Point = Point(10, 10);
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let p2: Point = Point(20, 20); // Put into different scope
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let p3: &Point = left_most(&p1, &p2);
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println!("left-most point: {:?}", p3);
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}
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