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