6eff103aa1
type error method suggestions use whitelisted identity-like conversions  Previously, on a type mismatch (and if this wasn't preëmpted by a higher-priority suggestion), we would look for argumentless methods returning the expected type, and list them in a `help` note. This had two major shortcomings: firstly, a lot of the suggestions didn't really make sense (if you used a &str where a String was expected, `.to_ascii_uppercase()` is probably not the solution you were hoping for). Secondly, we weren't generating suggestions from the most useful traits! We address the first problem with an internal `#[rustc_conversion_suggestion]` attribute meant to mark methods that keep the "same value" in the relevant sense, just converting the type. We address the second problem by making `FnCtxt.probe_for_return_type` pass the `ProbeScope::AllTraits` to `probe_op`: this would seem to be safe because grep reveals no other callers of `probe_for_return_type`. Also, structured suggestions are pretty and good for RLS and friends. Unfortunately, the trait probing is still not all one would hope for: at a minimum, we don't know how to rule out `into()` in cases where it wouldn't actually work, and we don't know how to rule in `.to_owned()` where it would. Issues #46459 and #46460 have been filed and are ref'd in a FIXME. This is hoped to resolve #42929, #44672, and #45777. |
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| .. | ||
| codegen | ||
| codegen-units | ||
| compile-fail | ||
| compile-fail-fulldeps | ||
| debuginfo | ||
| incremental | ||
| mir-opt | ||
| parse-fail | ||
| pretty | ||
| run-fail | ||
| run-fail-fulldeps | ||
| run-make | ||
| run-pass | ||
| run-pass-fulldeps | ||
| run-pass-valgrind | ||
| rustdoc | ||
| ui | ||
| ui-fulldeps | ||
| COMPILER_TESTS.md | ||
