mirror of https://github.com/rust-lang/rust
49 lines
775 B
Rust
49 lines
775 B
Rust
struct Foo {
|
|
inner: u32,
|
|
}
|
|
|
|
struct Bar {
|
|
inner: u32,
|
|
}
|
|
|
|
#[derive(Clone, Copy)]
|
|
struct Baz {
|
|
inner: u32,
|
|
}
|
|
|
|
impl From<Baz> for Bar {
|
|
fn from(other: Baz) -> Self {
|
|
Self {
|
|
inner: other.inner,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl From<Baz> for Foo {
|
|
fn from(other: Baz) -> Self {
|
|
Self {
|
|
inner: other.inner,
|
|
}
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
let x: Baz = Baz { inner: 42 };
|
|
|
|
// DOESN'T Compile: Multiple options!
|
|
let y = x.into(); //~ ERROR E0283
|
|
|
|
let y_1: Foo = x.into();
|
|
let y_2: Bar = x.into();
|
|
|
|
let z_1 = Foo::from(y_1);
|
|
let z_2 = Bar::from(y_2);
|
|
|
|
// No type annotations needed, the compiler KNOWS the type must be `Foo`!
|
|
let m = magic_foo(x);
|
|
}
|
|
|
|
fn magic_foo(arg: Baz) -> Foo {
|
|
arg.into()
|
|
}
|