rust/tests/ui/for/issue-20605.rs

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

16 lines
634 B
Rust
Raw Normal View History

2023-06-01 22:26:14 -05:00
//@ revisions: current next
//@ ignore-compare-mode-next-solver (explicit revisions)
2023-12-14 06:11:28 -06:00
//@[next] compile-flags: -Znext-solver
2023-06-01 22:26:14 -05:00
fn changer<'a>(mut things: Box<dyn Iterator<Item=&'a mut u8>>) {
for item in *things { *item = 0 }
Use root obligation on E0277 for some cases When encountering trait bound errors that satisfy some heuristics that tell us that the relevant trait for the user comes from the root obligation and not the current obligation, we use the root predicate for the main message. This allows to talk about "X doesn't implement Pattern<'_>" over the most specific case that just happened to fail, like "char doesn't implement Fn(&mut char)" in `tests/ui/traits/suggest-dereferences/root-obligation.rs` The heuristics are: - the type of the leaf predicate is (roughly) the same as the type from the root predicate, as a proxy for "we care about the root" - the leaf trait and the root trait are different, so as to avoid talking about `&mut T: Trait` and instead remain talking about `T: Trait` instead - the root trait is not `Unsize`, as to avoid talking about it in `tests/ui/coercion/coerce-issue-49593-box-never.rs`. ``` error[E0277]: the trait bound `&char: Pattern<'_>` is not satisfied --> $DIR/root-obligation.rs:6:38 | LL | .filter(|c| "aeiou".contains(c)) | -------- ^ the trait `Fn<(char,)>` is not implemented for `&char`, which is required by `&char: Pattern<'_>` | | | required by a bound introduced by this call | = note: required for `&char` to implement `FnOnce<(char,)>` = note: required for `&char` to implement `Pattern<'_>` note: required by a bound in `core::str::<impl str>::contains` --> $SRC_DIR/core/src/str/mod.rs:LL:COL help: consider dereferencing here | LL | .filter(|c| "aeiou".contains(*c)) | + ``` Fix #79359, fix #119983, fix #118779, cc #118415 (the suggestion needs to change).
2024-02-28 18:35:59 -06:00
//[current]~^ ERROR `dyn Iterator<Item = &'a mut u8>` is not an iterator
//[next]~^^ ERROR `dyn Iterator<Item = &'a mut u8>` is not an iterator
//[next]~| ERROR type `<dyn Iterator<Item = &'a mut u8> as IntoIterator>::Item` cannot be dereferenced
2023-12-14 06:11:28 -06:00
// FIXME(-Znext-solver): these error messages are horrible and have to be
2023-06-27 16:13:50 -05:00
// improved before we stabilize the new solver.
2023-06-01 22:26:14 -05:00
}
fn main() {}