fix bug for large_enum_variants
Fix the discussion problem in the issue of https://github.com/rust-lang/rust-clippy/issues/7666#issuecomment-919654291
About the false positive problem of case:
```rust
enum LargeEnum6 {
A,
B([u8;255]),
C([u8;200]),
}
```
changelog: Fix largest_enum_variant wrongly identifying the second largest variant.
Rustup
This needs a review this time. Especially 521bf8f0fa cc `@camsteffen` I think this is necessary now, because `itertools` is no longer a dependency of `clippy_utils` and therefore this path can't be found 🤔
( I forgot about the sync last week. I should get to document this process better, so other people can do it when I'm not around )
changelog: none
#7594: Adding new 'while_let_some_result' linting
Excited for the opportunity to contribute to Clippy! Since the latest Bay Area Rust Meetup, I've been looking for an opportunity and found it 😄
Please let me know how I can improve this PR! Much of it is similar to ``[`if_let_some_result`]``, but I followed the description in the issue to create its own linting rules. Looking forward to feedback, and continuing to work on Clippy in the future!
changelog: Renamed Lint: `if_let_some_result` is now called [`match_result_ok`]. Now also handles `while let` case.
bump clippy crates to edition 2021
Also helps with dogfooding edition 2021 a bit. :)
Tests passed locally.
---
changelog: bump edition from 2018 to 2021
Demote float_cmp to pedantic
See this issue: https://github.com/rust-lang/rust-clippy/issues/7666
This is one of the most frequently suppressed lints. It is deny-by-default. It is not actually clearly wrong, as there are many instances where direct float comparison is actually desirable. It is only after operating on floats that they may lose precision, and that depends greatly on the operation. As most correctness lints have a much higher standard of error, being based on hard and fast binary logic, this should not be amongst them.
A linter is not a substitute for observing the math carefully and running tests, and doing the desirable thing is even more likely to lead one to want exact comparisons.
changelog: Demote [`float_cmp`] from correctness to pedantic lints
Stop suggesting a float truncation that is not shorter
Fixes#7721.
Previously Clippy would say that a number has excessive precision even if it has the minimum possible precision for the floating point value that it corresponds to.
changelog: Fix [`excessive_precision`] being triggered on floats that are already written in shortest form
Introduce `Rvalue::ShallowInitBox`
Polished version of #88700.
Implements MCP rust-lang/compiler-team#460, and should allow #43596 to go forward.
In short, creating an empty box is split from a nullary-op `NullOp::Box` into two steps, first a call to `exchange_malloc`, then a `Rvalue::ShallowInitBox` which transmutes `*mut u8` to a shallow-initialized `Box<T>`. This allows the `exchange_malloc` call to unwind. Details can be found in the MCP.
`NullOp::Box` is not yet removed, purely to make reverting easier in case anything goes wrong as the result of this PR. If revert is needed a reversion of "Use Rvalue::ShallowInitBox for box expression" commit followed by a test bless should be sufficient.
Experiments in #88700 showed a very slight compile-time perf regression due to (supposedly) slightly more time spent in LLVM. We could omit unwind edge generation (in non-`oom=panic` case) in box expression MIR construction to restore perf; but I don't think it's necessary since runtime perf isn't affected and perf difference is rather small.
Be explicit about using Binder::dummy
This is somewhat of a late followup to the binder refactor PR. It removes `ToPredicate` and `ToPolyTraitImpls` that hide the use of `Binder::dummy`. While this does make code a bit more verbose, it allows us be more careful about where we create binders.
Another alternative here might be to add a new trait `ToBinder` or something with a `dummy()` fn. Which could still allow grepping but allows doing something like `trait_ref.dummy()` (but I also wonder if longer-term, it would be better to be even more explicit with a `bind_with_vars(ty::List::empty())` *but* that's not clear yet.
r? ``@nikomatsakis``
