diff --git a/tests/ui/impl-trait/recursive-bound-eval.rs b/tests/ui/impl-trait/recursive-bound-eval.rs new file mode 100644 index 0000000000000..f992cb3071a95 --- /dev/null +++ b/tests/ui/impl-trait/recursive-bound-eval.rs @@ -0,0 +1,18 @@ +pub trait Parser { + fn parse(&self) -> E; +} + +impl E> Parser for T { + fn parse(&self) -> E { + self() + } +} + +pub fn recursive_fn() -> impl Parser { + //~^ ERROR: cycle detected + move || recursive_fn().parse() + //~^ ERROR: type annotations needed + //~| ERROR: no method named `parse` found for opaque type +} + +fn main() {} diff --git a/tests/ui/impl-trait/recursive-bound-eval.stderr b/tests/ui/impl-trait/recursive-bound-eval.stderr new file mode 100644 index 0000000000000..c7283380234d9 --- /dev/null +++ b/tests/ui/impl-trait/recursive-bound-eval.stderr @@ -0,0 +1,42 @@ +error[E0282]: type annotations needed + --> $DIR/recursive-bound-eval.rs:13:28 + | +LL | move || recursive_fn().parse() + | ^^^^^ cannot infer type + +error[E0599]: no method named `parse` found for opaque type `impl Parser<_>` in the current scope + --> $DIR/recursive-bound-eval.rs:13:28 + | +LL | move || recursive_fn().parse() + | ^^^^^ method not found in `impl Parser<_>` + | + = help: items from traits can only be used if the trait is implemented and in scope +help: trait `Parser` which provides `parse` is implemented but not in scope; perhaps you want to import it + | +LL + use Parser; + | + +error[E0391]: cycle detected when computing type of opaque `recursive_fn::{opaque#0}` + --> $DIR/recursive-bound-eval.rs:11:29 + | +LL | pub fn recursive_fn() -> impl Parser { + | ^^^^^^^^^^^^^^ + | +note: ...which requires type-checking `recursive_fn`... + --> $DIR/recursive-bound-eval.rs:13:13 + | +LL | move || recursive_fn().parse() + | ^^^^^^^^^^^^^^ + = note: ...which requires evaluating trait selection obligation `recursive_fn::{opaque#0}: core::marker::Unpin`... + = note: ...which again requires computing type of opaque `recursive_fn::{opaque#0}`, completing the cycle +note: cycle used when computing type of `recursive_fn::{opaque#0}` + --> $DIR/recursive-bound-eval.rs:11:29 + | +LL | pub fn recursive_fn() -> impl Parser { + | ^^^^^^^^^^^^^^ + = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information + +error: aborting due to 3 previous errors + +Some errors have detailed explanations: E0282, E0391, E0599. +For more information about an error, try `rustc --explain E0282`.