Result<T, E> has an `ok()` method that adapts a Result<T,E> into an Option<T>.
It's possible to get around this adapter by writing Result<T,E>.map_or(None, Some).
This lint is implemented as a new variant of the existing
[`option_map_none` lint](https://github.com/rust-lang/rust-clippy/pull/2128)
useless Rc<Rc<T>>, Rc<Box<T>>, Rc<&T>, Box<&T>
refers to #2394
changelog: Add lints for Rc<Rc<T>> and Rc<Box<T>> and Rc<&T>, Box<&T>
this is based on top of another change #5310 so probably should go after that one.
Downgrade option_option to pedantic
Based on a search of my work codebase (\>500k lines) for `Option<Option<`, it looks like a bunch of reasonable uses to me. The documented motivation for this lint is:
> an optional optional value is logically the same thing as an optional value but has an unneeded extra level of wrapping
which seems a bit bogus in practice. For example a typical usage would look like:
```rust
let mut host: Option<String> = None;
let mut port: Option<i32> = None;
let mut payload: Option<Option<String>> = None;
for each field {
match field.name {
"host" => host = Some(...),
"port" => port = Some(...),
"payload" => payload = Some(...), // can be null or string
_ => return error,
}
}
let host = host.ok_or(...)?;
let port = port.ok_or(...)?;
let payload = payload.ok_or(...)?;
do_thing(host, port, payload)
```
This lint seems to fit right in with the pedantic group; I don't think linting on occurrences of `Option<Option<T>>` by default is justified.
---
changelog: Remove option_option from default set of enabled lints
Lint unnamed address comparisons
Functions and vtables have an insignificant address. Attempts to compare such addresses will lead to very surprising behaviour. For example: addresses of different functions could compare equal; two trait object pointers representing the same object and the same type could be unequal.
Lint against unnamed address comparisons to avoid issues like those in rust-lang/rust#69757 and rust-lang/rust#54685.
changelog: New lints: [`fn_address_comparisons`] [#5294](https://github.com/rust-lang/rust-clippy/pull/5294), [`vtable_address_comparisons`] [#5294](https://github.com/rust-lang/rust-clippy/pull/5294)
`unused_self` false positive
fixes#5351
Remove the for loop in `unused_self` so that lint enabled for one method doesn't trigger on another method.
changelog: Fix false positive in `unused_self` around lint gates on impl items
Lint for `pub(crate)` items that are not crate visible due to the visibility of the module that contains them
changelog: Add `redundant_pub_crate` lint
Closes#5274.
Improvement: Don't show function body in needless_lifetimes
Changes the span on which the lint is reported to point to only the
function return type instead of the entire function body.
Fixes#5284
changelog: none
add lint on File::read_to_string and File::read_to_end
Adds lint `verbose_file_reads` which checks for use of File::read_to_end and File::read_to_string.
Closes https://github.com/rust-lang/rust-clippy/issues/4916
changelog: add lint on File::{read_to_end, read_to_string}
Use `edition:2018` flag more widely
Now we recommend using `// edition:2018`, so let's use it more widely.
Also replace a too old example with new one in the docs.
changelog: none
redundant_pattern: take binding (ref, ref mut) into account in suggestion
fixes#5271
changelog: redundant_pattern: take binding (ref, ref mut) into account in suggestion (#5271)
Fix match single binding when in a let stmt
Fix bad suggestion when `match_single_binding` lints when inside a local (let) statement.
Fixes#5267
changelog: none
Resolve false positives of unnecessary_cast for non-decimal integers
This PR resolves false positives of `unnecessary_cast` for hexadecimal integers to floats and adds a corresponding test case.
Fixes: #5220
changelog: none
Add lint for .. use in fully binded struct
This PR adds the lint `match-wild-in-fully-binded-struct` to prevent the use of the `..` pattern when all fields of the struct are already binded.
Fixes: #638
changelog: Add [`rest_pat_in_fully_bound_structs`] lint to warn against the use of `..` in fully binded struct
Detect usage of custom floating-point abs implementation
Closes#5224
changelog: Enhance [`suboptimal_flops`] lint to detect manual implementations of the `abs` method
Whitelist unused attribute for use items.
This PR whitelists the `unused` attribute with `use` items and adds a corresponding test case.
Fixes: #5229
changelog: none
Add lint to detect floating point operations that can be computed more
accurately at the cost of performance. `cbrt`, `ln_1p` and `exp_m1`
library functions call their equivalent cmath implementations which is
slower but more accurate so moving checks for these under this new lint.
Merge the accuracy and efficiency lints into a single lint that
checks for improvements to accuracy, efficiency and readability
of floating-point expressions.
Move check for lossy whole-number floats out of `excessive_precision`
changelog: Add new lint `lossy_float_literal` to detect lossy whole number float literals and move it out of `excessive_precision` again.
Fixes#5201
Make it possible to correctly indent snippet_block snippets
This adds a `indent_relative_to` arg to the `{snippet,expr}_block` functions. This makes it possible to keep the correct indentation of block like suggestions.
In addition, this makes the `trim_multiline` function private and adds a `indent_of` function, to get the indentation of the first line of a span.
The suggestion of `needless_continue` cannot be made auto applicable, since it would be also necessary to remove code following the linted expression. (Well, maybe it is possible, but I don't know how to do it. Expanding the suggestion span to the last expression, that should be removed didn't work)
changelog: Improve suggestions, when blocks of code are involved
Port mitsuhiko's excessive bools lints
Closes#4 .
changelog: add `struct_excessive_bools` and `fn_params_excessive_bools` lints.
I moved is_trait_impl_item check because at first I implemented it as a late pass for some reason but then I realized it's actually an early lint. But it's a useful function to have, should I move it into a separate pr?
Do not lint `unnecessary_unwrap` in external macros
Fixes#5131
I think we shouldn't lint `{panicking, unnecessary}_unwrap` in macros, not just `assert!`.
changelog: Fix false positive in `unnecessary_unwrap`
add `let_underscore_lock` lint
closes#1574
changelog: add `let_underscore_lock` lint
I am not entirely sure about my docs/messages wording here, improvements are welcome
Clean up `span_lint` in `methods/mod.rs`
Uses `span_help_and_lint` instead of `span_lint` and `span_lint_and_sugg` instead of `span_lint_and_then`.
changelog: none
dont fire `possible_missing_comma` if intendation is present
Closes#4399
changelog: dont fire `possible_missing_comma` if intendation is present
I suspect there is already a utils function for indentation (but searching indent didn't yield a function for that), and my solution is certainly not universal, but it's probably the best we can do.
Detect usage of invalid atomic ordering in memory fences
Detect usage of `core::sync::atomic::{fence, compiler_fence}` with `Ordering::Relaxed` and suggest valid alternatives.
changelog: Extend `invalid_atomic_ordering` to lint memory fences
Fixes#5026
Avoid mut_key on types of unknown layout
This fixes#5020 by requiring a known layout for the key type before linting. Edit: This fixes#5043, too.
changelog: none
Keep the ordering in `nonminimal_bool` lint
I believe it shouldn't cause any regression but feel free to let me know if you have a doubtful example.
Also, splits up `booleans` ui test.
Fixes#5045
changelog: none
Autogenerate new lints
Add option in clippy_dev to automatically generate boilerplate code for adding new lints
example:
`./util/dev new_lint --name=iter_nth_zero --type=late`
Fixes#4942
changelog: none
