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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /src/test/ui/associated-types/param-env-normalize-cycle.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/test/ui/associated-types/param-env-normalize-cycle.rs')
-rw-r--r-- | src/test/ui/associated-types/param-env-normalize-cycle.rs | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/src/test/ui/associated-types/param-env-normalize-cycle.rs b/src/test/ui/associated-types/param-env-normalize-cycle.rs new file mode 100644 index 000000000..12db595ed --- /dev/null +++ b/src/test/ui/associated-types/param-env-normalize-cycle.rs @@ -0,0 +1,39 @@ +// Minimized case from typenum that didn't compile because: +// - We tried to normalize the ParamEnv of the second impl +// - This requires trying to normalize `GrEq<Self, Square<Square<U>>>` +// - This requires proving `Square<Square<U>>: Sized` so that the first impl +// applies +// - This requires Providing `Square<Square<U>>` is well-formed, so that we +// can use the `Sized` bound on `Mul::Output` +// - This requires proving `Square<U>: Mul` +// - But first we tried normalizing the whole obligation, including the +// ParamEnv, which leads to a cycle error. + +// check-pass + +trait PrivateSquareRoot {} + +pub trait Mul<Rhs = Self> { + type Output; +} + +pub trait IsGreaterOrEqual<Rhs> { + type Output; +} + +pub type Square<A> = <A as Mul>::Output; +pub type GrEq<A, B> = <A as IsGreaterOrEqual<B>>::Output; + +impl<A, B> IsGreaterOrEqual<B> for A { + type Output = (); +} + +impl<U> PrivateSquareRoot for U +where + U: Mul, + Square<U>: Mul, + GrEq<Self, Square<Square<U>>>: Sized, +{ +} + +fn main() {} |