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use std::ops::Add;
trait Trait<T> {
fn get(self) -> T;
}
struct Holder<T>(T);
impl<T> Trait<T> for Holder<T> {
fn get(self) -> T {
self.0
}
}
enum Either<L, R> {
Left(L),
Right(R),
}
impl<L, R> Either<L, R> {
fn converge<T>(self) -> T where L: Trait<T>, R: Trait<T> {
match self {
Either::Left(val) => val.get(),
Either::Right(val) => val.get(),
}
}
}
fn add_generic<A: Add<B>, B>(lhs: A, rhs: B) -> Either<
impl Trait<<A as Add<B>>::Output>,
impl Trait<<A as Add<B>>::Output>
> {
if true {
Either::Left(Holder(lhs + rhs))
} else {
Either::Right(Holder(lhs + rhs))
}
}
fn add_one(
value: u32,
) -> Either<impl Trait<<u32 as Add<u32>>::Output>, impl Trait<<u32 as Add<u32>>::Output>> {
//~^ ERROR: the trait bound `impl Trait<<u32 as Add>::Output>: Trait<u32>`
//~| ERROR: the trait bound `impl Trait<<u32 as Add>::Output>: Trait<u32>`
add_generic(value, 1u32)
}
pub fn main() {
add_one(3).converge();
}
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