rust-ape-example/src/bin/trait_ops.rs

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// ./src/trait/ops.md
use std::ops;
struct Foo;
struct Bar;
#[derive(Debug)]
struct FooBar;
#[derive(Debug)]
struct BarFoo;
// The `std::ops::Add` trait is used to specify the functionality of `+`.
// Here, we make `Add<Bar>` - the trait for addition with a RHS of type `Bar`.
// The following block implements the operation: Foo + Bar = FooBar
impl ops::Add<Bar> for Foo {
type Output = FooBar;
fn add(self, _rhs: Bar) -> FooBar {
println!("> Foo.add(Bar) was called");
FooBar
}
}
// By reversing the types, we end up implementing non-commutative addition.
// Here, we make `Add<Foo>` - the trait for addition with a RHS of type `Foo`.
// This block implements the operation: Bar + Foo = BarFoo
impl ops::Add<Foo> for Bar {
type Output = BarFoo;
fn add(self, _rhs: Foo) -> BarFoo {
println!("> Bar.add(Foo) was called");
BarFoo
}
}
fn part0() {
println!("Foo + Bar = {:?}", Foo + Bar);
println!("Bar + Foo = {:?}", Bar + Foo);
}
pub fn main() {
part0();
}