3.2.3 关联类型
03-关联类型 — Comprehensive Rust
译文 · 基于 Comprehensive Rust
原文链接: https://google.github.io/comprehensive-rust/methods-and-traits/traits/associated-types.html
3.2.3 关联类型
关联类型（associated types）是由 trait 实现方提供的占位类型。
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| // Copyright 2024 Google LLC
// SPDX-License-Identifier: Apache-2.0
#[derive(Debug)]
struct Meters(i32);
#[derive(Debug)]
struct MetersSquared(i32);
trait Multiply {
type Output;
fn multiply(&self, other: &Self) -> Self::Output;
}
impl Multiply for Meters {
type Output = MetersSquared;
fn multiply(&self, other: &Self) -> Self::Output {
MetersSquared(self.0 * other.0)
}
}
fn main() {
println!("{:?}", Meters(10).multiply(&Meters(20)));
}
|