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Diffstat (limited to '')
-rw-r--r-- | tests/ui/traits/new-solver/normalizes_to_ignores_unnormalizable_candidate.rs | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/tests/ui/traits/new-solver/normalizes_to_ignores_unnormalizable_candidate.rs b/tests/ui/traits/new-solver/normalizes_to_ignores_unnormalizable_candidate.rs new file mode 100644 index 000000000..46343241b --- /dev/null +++ b/tests/ui/traits/new-solver/normalizes_to_ignores_unnormalizable_candidate.rs @@ -0,0 +1,40 @@ +// [no_self_infer] check-pass +// compile-flags: -Ztrait-solver=next +// revisions: self_infer no_self_infer + +// checks that the new solver is smart enough to infer `?0 = U` when solving: +// `normalizes-to(<Vec<?0> as Trait>::Assoc, u8)` +// with `normalizes-to(<Vec<U> as Trait>::Assoc, u8)` in the paramenv even when +// there is a separate `Vec<T>: Trait` bound in the paramenv. +// +// FIXME(-Ztrait-solver=next) +// This could also compile for `normalizes-to(<?0 as Trait>::Assoc, u8)` but +// we currently immediately consider a goal ambiguous if the self type is an +// inference variable. + +trait Trait { + type Assoc; +} + +fn foo<T: Trait<Assoc = u8>>(x: T) {} + +#[cfg(self_infer)] +fn unconstrained<T>() -> T { + todo!() +} + +#[cfg(no_self_infer)] +fn unconstrained<T>() -> Vec<T> { + todo!() +} + +fn bar<T, U>() +where + Vec<T>: Trait, + Vec<U>: Trait<Assoc = u8>, +{ + foo(unconstrained()) + //[self_infer]~^ ERROR type annotations needed +} + +fn main() {} |