rust/compiler/rustc_trait_selection
Matthias Krüger 5ebacd1b3c
Rollup merge of #135965 - estebank:shorten-ty-sugg, r=lcnr
In "specify type" suggestion, skip type params that are already known

When we suggest specifying a type for an expression or pattern, like in a `let` binding, we previously would print the entire type as the type system knew it. We now look at the params that have *no* inference variables, so they are fully known to the type system which means that they don't need to be specified.

This helps in suggestions for types that are really long, because we can usually skip most of the type params and make the annotation as short as possible:

```
error[E0282]: type annotations needed for `Result<_, ((..., ..., ..., ...), ..., ..., ...)>`
  --> $DIR/really-long-type-in-let-binding-without-sufficient-type-info.rs:7:9
   |
LL |     let y = Err(x);
   |         ^   ------ type must be known at this point
   |
help: consider giving `y` an explicit type, where the type for type parameter `T` is specified
   |
LL |     let y: Result<T, _> = Err(x);
   |          ++++++++++++++
```

Fix #135919.
2025-02-12 06:07:36 +01:00
..
src Rollup merge of #135965 - estebank:shorten-ty-sugg, r=lcnr 2025-02-12 06:07:36 +01:00
Cargo.toml rename rustc_attr to rustc_attr_parsing and create rustc_attr_data_structures 2024-12-16 19:08:19 +01:00
messages.ftl Rework rustc_dump_vtable 2025-01-30 15:30:04 +00:00