Given `trait Any: 'static` and a `struct` with a `Box<dyn Any + 'a>` field, point at the `'static` bound in `Any` to explain why `'a: 'static`.
```
error[E0478]: lifetime bound not satisfied
--> f202.rs:2:12
|
2 | value: Box<dyn std::any::Any + 'a>,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
note: lifetime parameter instantiated with the lifetime `'a` as defined here
--> f202.rs:1:14
|
1 | struct Hello<'a> {
| ^^
note: but lifetime parameter must outlive the static lifetime
--> /home/gh-estebank/rust/library/core/src/any.rs:113:16
|
113 | pub trait Any: 'static {
| ^^^^^^^
```
Partially address #33652.
Shrink `TyKind::FnPtr`.
By splitting the `FnSig` within `TyKind::FnPtr` into `FnSigTys` and `FnHeader`, which can be packed more efficiently. This reduces the size of the hot `TyKind` type from 32 bytes to 24 bytes on 64-bit platforms. This reduces peak memory usage by a few percent on some benchmarks. It also reduces cache misses and page faults similarly, though this doesn't translate to clear cycles or wall-time improvements on CI.
r? `@compiler-errors`
By splitting the `FnSig` within `TyKind::FnPtr` into `FnSigTys` and
`FnHeader`, which can be packed more efficiently. This reduces the size
of the hot `TyKind` type from 32 bytes to 24 bytes on 64-bit platforms.
This reduces peak memory usage by a few percent on some benchmarks. It
also reduces cache misses and page faults similarly, though this doesn't
translate to clear cycles or wall-time improvements on CI.
Suggest using precise capturing for hidden type that captures region
Adjusts the "add `+ '_`" suggestion for opaques to instead suggest adding or reusing the `+ use<>` in the opaque.
r? oli-obk or please re-roll if you're busy!
Make `push_outlives_components` into a `TypeVisitor`
This involves removing the `visited: &mut SsoHashSet<GenericArg<'tcx>>` that is being passed around the `VerifyBoundCx`. The fact that we were using it when decomposing different type tests seems sketchy, so I don't think, though it may technically result in us registering more redundant outlives components 🤷
I did end up deleting some of the comments that referred back to RFC 1214 during this refactor. I can add them back if you think they were useful.
r? lcnr
Make `can_eq` process obligations (almost) everywhere
Move `can_eq` to an extension trait on `InferCtxt` in `rustc_trait_selection`, and change it so that it processes obligations. This should strengthen it to be more accurate in some cases, but is most important for the new trait solver which delays relating aliases to `AliasRelate` goals. Without this, we always basically just return true when passing aliases to `can_eq`, which can lead to weird errors, for example #127149.
I'm not actually certain if we should *have* `can_eq` be called on the good path. In cases where we need `can_eq`, we probably should just be using a regular probe.
Fixes#127149
r? lcnr
Don't suggest awaiting in closure patterns
Fixes#126903.
For
```rust
async fn do_async() {}
fn main() {
Some(do_async()).map(|()| {});
}
```
the error is now
```rust
error[E0308]: mismatched types
--> src/main.rs:4:27
|
4 | Some(do_async()).map(|()| {});
| ^^
| |
| expected future, found `()`
| expected due to this
|
= note: expected opaque type `impl Future<Output = ()>`
found unit type `()`
```
Ideally, if `main` were to be `async`, it should be
```rs
error[E0308]: mismatched types
--> src/main.rs:4:27
|
4 | Some(do_async()).map(|()| {});
| ^^
| |
| expected future, found `()`
| expected due to this
|
= note: expected opaque type `impl Future<Output = ()>`
found unit type `()`
help: consider `await`ing on the `Future`
|
4 | Some(do_async().await).map(|()| {});
| ++++++
```
However, this would mean `FnCtx::check_pat_top` would have to be called with an `origin_expr` in `rustc_hir_typeck::check::check_fn`, and that expr would have to be somehow plumbed through `FnCtxt::check_expr_closure` and closure signature deduction. I'm willing to work on the plumbing but unsure how to start.
Most modules have such a blank line, but some don't. Inserting the blank
line makes it clearer that the `//!` comments are describing the entire
module, rather than the `use` declaration(s) that immediately follows.
Uplift next trait solver to `rustc_next_trait_solver`
🎉
There's so many FIXMEs! Sorry! Ideally this merges with the FIXMEs and we track and squash them over the near future.
Also, this still doesn't build on anything other than rustc. I still need to fix `feature = "nightly"` in `rustc_type_ir`, and remove and fix all the nightly feature usage in the new trait solver (notably: let-chains).
Also, sorry `@lcnr` I know you asked for me to separate the commit where we `mv rustc_trait_selection/solve/... rustc_next_trait_solver/solve/...`, but I had already done all the work by that point. Luckily, `git` understands the file moves so it should still be relatively reviewable.
If this is still very difficult to review, then I can do some rebasing magic to try to separate this out. Please let me know!
r? lcnr
