mod chars_next_cmp_with_unwrap;
mod clone_on_copy;
mod clone_on_ref_ptr;
+mod cloned_instead_of_copied;
mod expect_fun_call;
mod expect_used;
+mod extend_with_drain;
mod filetype_is_file;
-mod filter_flat_map;
mod filter_map;
-mod filter_map_flat_map;
mod filter_map_identity;
-mod filter_map_map;
mod filter_map_next;
mod filter_next;
mod flat_map_identity;
+mod flat_map_option;
mod from_iter_instead_of_collect;
mod get_unwrap;
mod implicit_clone;
mod iter_next_slice;
mod iter_nth;
mod iter_nth_zero;
+mod iter_overeager_cloned;
mod iter_skip_next;
mod iterator_step_by_zero;
mod manual_saturating_arithmetic;
+mod manual_str_repeat;
mod map_collect_result_unit;
mod map_flatten;
+mod map_identity;
mod map_unwrap_or;
mod ok_expect;
mod option_as_ref_deref;
mod single_char_pattern;
mod single_char_push_string;
mod skip_while_next;
+mod str_splitn;
mod string_extend_chars;
mod suspicious_map;
+mod suspicious_splitn;
mod uninit_assumed_init;
mod unnecessary_filter_map;
mod unnecessary_fold;
+mod unnecessary_iter_cloned;
mod unnecessary_lazy_eval;
+mod unnecessary_to_owned;
+mod unwrap_or_else_default;
mod unwrap_used;
mod useless_asref;
mod utils;
mod zst_offset;
use bind_instead_of_map::BindInsteadOfMap;
+use clippy_utils::consts::{constant, Constant};
use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
use clippy_utils::ty::{contains_adt_constructor, contains_ty, implements_trait, is_copy, is_type_diagnostic_item};
-use clippy_utils::{contains_return, get_trait_def_id, in_macro, iter_input_pats, paths, return_ty};
+use clippy_utils::{contains_return, get_trait_def_id, iter_input_pats, meets_msrv, msrvs, paths, return_ty};
use if_chain::if_chain;
use rustc_hir as hir;
use rustc_hir::def::Res;
use rustc_hir::{Expr, ExprKind, PrimTy, QPath, TraitItem, TraitItemKind};
use rustc_lint::{LateContext, LateLintPass, LintContext};
use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::{self, TraitRef, Ty, TyS};
+use rustc_middle::ty::{self, TraitRef, Ty};
use rustc_semver::RustcVersion;
use rustc_session::{declare_tool_lint, impl_lint_pass};
-use rustc_span::symbol::SymbolStr;
use rustc_span::{sym, Span};
use rustc_typeck::hir_ty_to_ty;
declare_clippy_lint! {
- /// **What it does:** Checks for `.unwrap()` calls on `Option`s and on `Result`s.
+ /// ### What it does
+ /// Checks for usages of `cloned()` on an `Iterator` or `Option` where
+ /// `copied()` could be used instead.
///
- /// **Why is this bad?** It is better to handle the `None` or `Err` case,
+ /// ### Why is this bad?
+ /// `copied()` is better because it guarantees that the type being cloned
+ /// implements `Copy`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// [1, 2, 3].iter().cloned();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// [1, 2, 3].iter().copied();
+ /// ```
+ #[clippy::version = "1.53.0"]
+ pub CLONED_INSTEAD_OF_COPIED,
+ pedantic,
+ "used `cloned` where `copied` could be used instead"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `_.cloned().<func>()` where call to `.cloned()` can be postponed.
+ ///
+ /// ### Why is this bad?
+ /// It's often inefficient to clone all elements of an iterator, when eventually, only some
+ /// of them will be consumed.
+ ///
+ /// ### Examples
+ /// ```rust
+ /// # let vec = vec!["string".to_string()];
+ ///
+ /// // Bad
+ /// vec.iter().cloned().take(10);
+ ///
+ /// // Good
+ /// vec.iter().take(10).cloned();
+ ///
+ /// // Bad
+ /// vec.iter().cloned().last();
+ ///
+ /// // Good
+ /// vec.iter().last().cloned();
+ ///
+ /// ```
+ /// ### Known Problems
+ /// This `lint` removes the side of effect of cloning items in the iterator.
+ /// A code that relies on that side-effect could fail.
+ ///
+ #[clippy::version = "1.59.0"]
+ pub ITER_OVEREAGER_CLONED,
+ perf,
+ "using `cloned()` early with `Iterator::iter()` can lead to some performance inefficiencies"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usages of `Iterator::flat_map()` where `filter_map()` could be
+ /// used instead.
+ ///
+ /// ### Why is this bad?
+ /// When applicable, `filter_map()` is more clear since it shows that
+ /// `Option` is used to produce 0 or 1 items.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let nums: Vec<i32> = ["1", "2", "whee!"].iter().flat_map(|x| x.parse().ok()).collect();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let nums: Vec<i32> = ["1", "2", "whee!"].iter().filter_map(|x| x.parse().ok()).collect();
+ /// ```
+ #[clippy::version = "1.53.0"]
+ pub FLAT_MAP_OPTION,
+ pedantic,
+ "used `flat_map` where `filter_map` could be used instead"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `.unwrap()` calls on `Option`s and on `Result`s.
+ ///
+ /// ### Why is this bad?
+ /// It is better to handle the `None` or `Err` case,
/// or at least call `.expect(_)` with a more helpful message. Still, for a lot of
/// quick-and-dirty code, `unwrap` is a good choice, which is why this lint is
/// `Allow` by default.
/// messages on display. Therefore, it may be beneficial to look at the places
/// where they may get displayed. Activate this lint to do just that.
///
- /// **Known problems:** None.
- ///
- /// **Examples:**
+ /// ### Examples
/// ```rust
/// # let opt = Some(1);
///
/// // Good
/// res.expect("more helpful message");
/// ```
+ #[clippy::version = "1.45.0"]
pub UNWRAP_USED,
restriction,
"using `.unwrap()` on `Result` or `Option`, which should at least get a better message using `expect()`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for `.expect()` calls on `Option`s and `Result`s.
+ /// ### What it does
+ /// Checks for `.expect()` calls on `Option`s and `Result`s.
///
- /// **Why is this bad?** Usually it is better to handle the `None` or `Err` case.
+ /// ### Why is this bad?
+ /// Usually it is better to handle the `None` or `Err` case.
/// Still, for a lot of quick-and-dirty code, `expect` is a good choice, which is why
/// this lint is `Allow` by default.
///
/// values. Normally, you want to implement more sophisticated error handling,
/// and propagate errors upwards with `?` operator.
///
- /// **Known problems:** None.
- ///
- /// **Examples:**
+ /// ### Examples
/// ```rust,ignore
/// # let opt = Some(1);
///
/// res?;
/// # Ok::<(), ()>(())
/// ```
+ #[clippy::version = "1.45.0"]
pub EXPECT_USED,
restriction,
"using `.expect()` on `Result` or `Option`, which might be better handled"
}
declare_clippy_lint! {
- /// **What it does:** Checks for methods that should live in a trait
+ /// ### What it does
+ /// Checks for methods that should live in a trait
/// implementation of a `std` trait (see [llogiq's blog
/// post](http://llogiq.github.io/2015/07/30/traits.html) for further
/// information) instead of an inherent implementation.
///
- /// **Why is this bad?** Implementing the traits improve ergonomics for users of
+ /// ### Why is this bad?
+ /// Implementing the traits improve ergonomics for users of
/// the code, often with very little cost. Also people seeing a `mul(...)`
/// method
/// may expect `*` to work equally, so you should have good reason to disappoint
/// them.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// struct X;
/// impl X {
/// }
/// }
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub SHOULD_IMPLEMENT_TRAIT,
style,
"defining a method that should be implementing a std trait"
}
declare_clippy_lint! {
- /// **What it does:** Checks for methods with certain name prefixes and which
+ /// ### What it does
+ /// Checks for methods with certain name prefixes and which
/// doesn't match how self is taken. The actual rules are:
///
/// |Prefix |Postfix |`self` taken | `self` type |
/// The method signature is controlled by the trait and often `&self` is required for all types that implement the trait
/// (see e.g. the `std::string::ToString` trait).
///
+ /// Clippy allows `Pin<&Self>` and `Pin<&mut Self>` if `&self` and `&mut self` is required.
+ ///
/// Please find more info here:
/// https://rust-lang.github.io/api-guidelines/naming.html#ad-hoc-conversions-follow-as_-to_-into_-conventions-c-conv
///
- /// **Why is this bad?** Consistency breeds readability. If you follow the
+ /// ### Why is this bad?
+ /// Consistency breeds readability. If you follow the
/// conventions, your users won't be surprised that they, e.g., need to supply a
/// mutable reference to a `as_..` function.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # struct X;
/// impl X {
/// }
/// }
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub WRONG_SELF_CONVENTION,
style,
"defining a method named with an established prefix (like \"into_\") that takes `self` with the wrong convention"
}
declare_clippy_lint! {
- /// **What it does:** This is the same as
- /// [`wrong_self_convention`](#wrong_self_convention), but for public items.
+ /// ### What it does
+ /// Checks for usage of `ok().expect(..)`.
///
- /// **Why is this bad?** See [`wrong_self_convention`](#wrong_self_convention).
+ /// ### Why is this bad?
+ /// Because you usually call `expect()` on the `Result`
+ /// directly to get a better error message.
///
- /// **Known problems:** Actually *renaming* the function may break clients if
- /// the function is part of the public interface. In that case, be mindful of
- /// the stability guarantees you've given your users.
+ /// ### Known problems
+ /// The error type needs to implement `Debug`
///
- /// **Example:**
+ /// ### Example
/// ```rust
- /// # struct X;
- /// impl<'a> X {
- /// pub fn as_str(self) -> &'a str {
- /// "foo"
- /// }
- /// }
+ /// # let x = Ok::<_, ()>(());
+ ///
+ /// // Bad
+ /// x.ok().expect("why did I do this again?");
+ ///
+ /// // Good
+ /// x.expect("why did I do this again?");
/// ```
- pub WRONG_PUB_SELF_CONVENTION,
- restriction,
- "defining a public method named with an established prefix (like \"into_\") that takes `self` with the wrong convention"
+ #[clippy::version = "pre 1.29.0"]
+ pub OK_EXPECT,
+ style,
+ "using `ok().expect()`, which gives worse error messages than calling `expect` directly on the Result"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `ok().expect(..)`.
- ///
- /// **Why is this bad?** Because you usually call `expect()` on the `Result`
- /// directly to get a better error message.
+ /// ### What it does
+ /// Checks for usages of `_.unwrap_or_else(Default::default)` on `Option` and
+ /// `Result` values.
///
- /// **Known problems:** The error type needs to implement `Debug`
+ /// ### Why is this bad?
+ /// Readability, these can be written as `_.unwrap_or_default`, which is
+ /// simpler and more concise.
///
- /// **Example:**
+ /// ### Examples
/// ```rust
- /// # let x = Ok::<_, ()>(());
+ /// # let x = Some(1);
///
/// // Bad
- /// x.ok().expect("why did I do this again?");
+ /// x.unwrap_or_else(Default::default);
+ /// x.unwrap_or_else(u32::default);
///
/// // Good
- /// x.expect("why did I do this again?");
+ /// x.unwrap_or_default();
/// ```
- pub OK_EXPECT,
+ #[clippy::version = "1.56.0"]
+ pub UNWRAP_OR_ELSE_DEFAULT,
style,
- "using `ok().expect()`, which gives worse error messages than calling `expect` directly on the Result"
+ "using `.unwrap_or_else(Default::default)`, which is more succinctly expressed as `.unwrap_or_default()`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `option.map(_).unwrap_or(_)` or `option.map(_).unwrap_or_else(_)` or
+ /// ### What it does
+ /// Checks for usage of `option.map(_).unwrap_or(_)` or `option.map(_).unwrap_or_else(_)` or
/// `result.map(_).unwrap_or_else(_)`.
///
- /// **Why is this bad?** Readability, these can be written more concisely (resp.) as
+ /// ### Why is this bad?
+ /// Readability, these can be written more concisely (resp.) as
/// `option.map_or(_, _)`, `option.map_or_else(_, _)` and `result.map_or_else(_, _)`.
///
- /// **Known problems:** The order of the arguments is not in execution order
+ /// ### Known problems
+ /// The order of the arguments is not in execution order
///
- /// **Examples:**
+ /// ### Examples
/// ```rust
/// # let x = Some(1);
///
/// // Good
/// x.map_or_else(some_function, |a| a + 1);
/// ```
+ #[clippy::version = "1.45.0"]
pub MAP_UNWRAP_OR,
pedantic,
"using `.map(f).unwrap_or(a)` or `.map(f).unwrap_or_else(func)`, which are more succinctly expressed as `map_or(a, f)` or `map_or_else(a, f)`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.map_or(None, _)`.
+ /// ### What it does
+ /// Checks for usage of `_.map_or(None, _)`.
///
- /// **Why is this bad?** Readability, this can be written more concisely as
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
/// `_.and_then(_)`.
///
- /// **Known problems:** The order of the arguments is not in execution order.
+ /// ### Known problems
+ /// The order of the arguments is not in execution order.
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let opt = Some(1);
///
/// // Good
/// opt.and_then(|a| Some(a + 1));
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub OPTION_MAP_OR_NONE,
style,
"using `Option.map_or(None, f)`, which is more succinctly expressed as `and_then(f)`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.map_or(None, Some)`.
+ /// ### What it does
+ /// Checks for usage of `_.map_or(None, Some)`.
///
- /// **Why is this bad?** Readability, this can be written more concisely as
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
/// `_.ok()`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
- ///
+ /// ### Example
/// Bad:
/// ```rust
/// # let r: Result<u32, &str> = Ok(1);
/// # let r: Result<u32, &str> = Ok(1);
/// assert_eq!(Some(1), r.ok());
/// ```
+ #[clippy::version = "1.44.0"]
pub RESULT_MAP_OR_INTO_OPTION,
style,
"using `Result.map_or(None, Some)`, which is more succinctly expressed as `ok()`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.and_then(|x| Some(y))`, `_.and_then(|x| Ok(y))` or
+ /// ### What it does
+ /// Checks for usage of `_.and_then(|x| Some(y))`, `_.and_then(|x| Ok(y))` or
/// `_.or_else(|x| Err(y))`.
///
- /// **Why is this bad?** Readability, this can be written more concisely as
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
/// `_.map(|x| y)` or `_.map_err(|x| y)`.
///
- /// **Known problems:** None
- ///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// # fn opt() -> Option<&'static str> { Some("42") }
/// # fn res() -> Result<&'static str, &'static str> { Ok("42") }
/// let _ = res().map(|s| if s.len() == 42 { 10 } else { 20 });
/// let _ = res().map_err(|s| if s.len() == 42 { 10 } else { 20 });
/// ```
+ #[clippy::version = "1.45.0"]
pub BIND_INSTEAD_OF_MAP,
complexity,
"using `Option.and_then(|x| Some(y))`, which is more succinctly expressed as `map(|x| y)`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.filter(_).next()`.
+ /// ### What it does
+ /// Checks for usage of `_.filter(_).next()`.
///
- /// **Why is this bad?** Readability, this can be written more concisely as
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
/// `_.find(_)`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let vec = vec![1];
/// vec.iter().filter(|x| **x == 0).next();
/// # let vec = vec![1];
/// vec.iter().find(|x| **x == 0);
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub FILTER_NEXT,
complexity,
"using `filter(p).next()`, which is more succinctly expressed as `.find(p)`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.skip_while(condition).next()`.
+ /// ### What it does
+ /// Checks for usage of `_.skip_while(condition).next()`.
///
- /// **Why is this bad?** Readability, this can be written more concisely as
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
/// `_.find(!condition)`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let vec = vec![1];
/// vec.iter().skip_while(|x| **x == 0).next();
/// # let vec = vec![1];
/// vec.iter().find(|x| **x != 0);
/// ```
+ #[clippy::version = "1.42.0"]
pub SKIP_WHILE_NEXT,
complexity,
"using `skip_while(p).next()`, which is more succinctly expressed as `.find(!p)`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.map(_).flatten(_)` on `Iterator` and `Option`
- ///
- /// **Why is this bad?** Readability, this can be written more concisely as
- /// `_.flat_map(_)`
+ /// ### What it does
+ /// Checks for usage of `_.map(_).flatten(_)` on `Iterator` and `Option`
///
- /// **Known problems:**
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
+ /// `_.flat_map(_)` for `Iterator` or `_.and_then(_)` for `Option`
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let vec = vec![vec![1]];
+ /// let opt = Some(5);
///
/// // Bad
/// vec.iter().map(|x| x.iter()).flatten();
+ /// opt.map(|x| Some(x * 2)).flatten();
///
/// // Good
/// vec.iter().flat_map(|x| x.iter());
+ /// opt.and_then(|x| Some(x * 2));
/// ```
+ #[clippy::version = "1.31.0"]
pub MAP_FLATTEN,
- pedantic,
+ complexity,
"using combinations of `flatten` and `map` which can usually be written as a single method call"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.filter(_).map(_)`,
- /// `_.filter(_).flat_map(_)`, `_.filter_map(_).flat_map(_)` and similar.
- ///
- /// **Why is this bad?** Readability, this can be written more concisely as
- /// `_.filter_map(_)`.
- ///
- /// **Known problems:** Often requires a condition + Option/Iterator creation
- /// inside the closure.
- ///
- /// **Example:**
- /// ```rust
- /// let vec = vec![1];
- ///
- /// // Bad
- /// vec.iter().filter(|x| **x == 0).map(|x| *x * 2);
- ///
- /// // Good
- /// vec.iter().filter_map(|x| if *x == 0 {
- /// Some(*x * 2)
- /// } else {
- /// None
- /// });
- /// ```
- pub FILTER_MAP,
- pedantic,
- "using combinations of `filter`, `map`, `filter_map` and `flat_map` which can usually be written as a single method call"
-}
-
-declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.filter(_).map(_)` that can be written more simply
+ /// ### What it does
+ /// Checks for usage of `_.filter(_).map(_)` that can be written more simply
/// as `filter_map(_)`.
///
- /// **Why is this bad?** Redundant code in the `filter` and `map` operations is poor style and
+ /// ### Why is this bad?
+ /// Redundant code in the `filter` and `map` operations is poor style and
/// less performant.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// Bad:
/// ```rust
/// (0_i32..10)
/// ```rust
/// (0_i32..10).filter_map(|n| n.checked_add(1));
/// ```
+ #[clippy::version = "1.51.0"]
pub MANUAL_FILTER_MAP,
complexity,
"using `_.filter(_).map(_)` in a way that can be written more simply as `filter_map(_)`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.find(_).map(_)` that can be written more simply
+ /// ### What it does
+ /// Checks for usage of `_.find(_).map(_)` that can be written more simply
/// as `find_map(_)`.
///
- /// **Why is this bad?** Redundant code in the `find` and `map` operations is poor style and
+ /// ### Why is this bad?
+ /// Redundant code in the `find` and `map` operations is poor style and
/// less performant.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// Bad:
/// ```rust
/// (0_i32..10)
/// ```rust
/// (0_i32..10).find_map(|n| n.checked_add(1));
/// ```
+ #[clippy::version = "1.51.0"]
pub MANUAL_FIND_MAP,
complexity,
"using `_.find(_).map(_)` in a way that can be written more simply as `find_map(_)`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.filter_map(_).next()`.
+ /// ### What it does
+ /// Checks for usage of `_.filter_map(_).next()`.
///
- /// **Why is this bad?** Readability, this can be written more concisely as
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
/// `_.find_map(_)`.
///
- /// **Known problems:** None
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// (0..3).filter_map(|x| if x == 2 { Some(x) } else { None }).next();
/// ```
/// ```rust
/// (0..3).find_map(|x| if x == 2 { Some(x) } else { None });
/// ```
+ #[clippy::version = "1.36.0"]
pub FILTER_MAP_NEXT,
pedantic,
"using combination of `filter_map` and `next` which can usually be written as a single method call"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `flat_map(|x| x)`.
+ /// ### What it does
+ /// Checks for usage of `flat_map(|x| x)`.
///
- /// **Why is this bad?** Readability, this can be written more concisely by using `flatten`.
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely by using `flatten`.
///
- /// **Known problems:** None
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let iter = vec![vec![0]].into_iter();
/// iter.flat_map(|x| x);
/// # let iter = vec![vec![0]].into_iter();
/// iter.flatten();
/// ```
+ #[clippy::version = "1.39.0"]
pub FLAT_MAP_IDENTITY,
complexity,
"call to `flat_map` where `flatten` is sufficient"
}
declare_clippy_lint! {
- /// **What it does:** Checks for an iterator or string search (such as `find()`,
+ /// ### What it does
+ /// Checks for an iterator or string search (such as `find()`,
/// `position()`, or `rposition()`) followed by a call to `is_some()` or `is_none()`.
///
- /// **Why is this bad?** Readability, this can be written more concisely as:
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as:
/// * `_.any(_)`, or `_.contains(_)` for `is_some()`,
/// * `!_.any(_)`, or `!_.contains(_)` for `is_none()`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let vec = vec![1];
/// vec.iter().find(|x| **x == 0).is_some();
///
/// let _ = !"hello world".contains("world");
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub SEARCH_IS_SOME,
complexity,
"using an iterator or string search followed by `is_some()` or `is_none()`, which is more succinctly expressed as a call to `any()` or `contains()` (with negation in case of `is_none()`)"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `.chars().next()` on a `str` to check
+ /// ### What it does
+ /// Checks for usage of `.chars().next()` on a `str` to check
/// if it starts with a given char.
///
- /// **Why is this bad?** Readability, this can be written more concisely as
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
/// `_.starts_with(_)`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let name = "foo";
/// if name.chars().next() == Some('_') {};
/// let name = "foo";
/// if name.starts_with('_') {};
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub CHARS_NEXT_CMP,
style,
"using `.chars().next()` to check if a string starts with a char"
}
declare_clippy_lint! {
- /// **What it does:** Checks for calls to `.or(foo(..))`, `.unwrap_or(foo(..))`,
+ /// ### What it does
+ /// Checks for calls to `.or(foo(..))`, `.unwrap_or(foo(..))`,
/// etc., and suggests to use `or_else`, `unwrap_or_else`, etc., or
/// `unwrap_or_default` instead.
///
- /// **Why is this bad?** The function will always be called and potentially
+ /// ### Why is this bad?
+ /// The function will always be called and potentially
/// allocate an object acting as the default.
///
- /// **Known problems:** If the function has side-effects, not calling it will
+ /// ### Known problems
+ /// If the function has side-effects, not calling it will
/// change the semantic of the program, but you shouldn't rely on that anyway.
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let foo = Some(String::new());
/// foo.unwrap_or(String::new());
/// # let foo = Some(String::new());
/// foo.unwrap_or_default();
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub OR_FUN_CALL,
perf,
"using any `*or` method with a function call, which suggests `*or_else`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for calls to `.expect(&format!(...))`, `.expect(foo(..))`,
+ /// ### What it does
+ /// Checks for calls to `.expect(&format!(...))`, `.expect(foo(..))`,
/// etc., and suggests to use `unwrap_or_else` instead
///
- /// **Why is this bad?** The function will always be called.
+ /// ### Why is this bad?
+ /// The function will always be called.
///
- /// **Known problems:** If the function has side-effects, not calling it will
+ /// ### Known problems
+ /// If the function has side-effects, not calling it will
/// change the semantics of the program, but you shouldn't rely on that anyway.
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let foo = Some(String::new());
/// # let err_code = "418";
/// # let err_msg = "I'm a teapot";
/// foo.unwrap_or_else(|| panic!("Err {}: {}", err_code, err_msg));
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub EXPECT_FUN_CALL,
perf,
"using any `expect` method with a function call"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `.clone()` on a `Copy` type.
+ /// ### What it does
+ /// Checks for usage of `.clone()` on a `Copy` type.
///
- /// **Why is this bad?** The only reason `Copy` types implement `Clone` is for
+ /// ### Why is this bad?
+ /// The only reason `Copy` types implement `Clone` is for
/// generics, not for using the `clone` method on a concrete type.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// 42u64.clone();
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub CLONE_ON_COPY,
complexity,
"using `clone` on a `Copy` type"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `.clone()` on a ref-counted pointer,
+ /// ### What it does
+ /// Checks for usage of `.clone()` on a ref-counted pointer,
/// (`Rc`, `Arc`, `rc::Weak`, or `sync::Weak`), and suggests calling Clone via unified
/// function syntax instead (e.g., `Rc::clone(foo)`).
///
- /// **Why is this bad?** Calling '.clone()' on an Rc, Arc, or Weak
+ /// ### Why is this bad?
+ /// Calling '.clone()' on an Rc, Arc, or Weak
/// can obscure the fact that only the pointer is being cloned, not the underlying
/// data.
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # use std::rc::Rc;
/// let x = Rc::new(1);
/// // Good
/// Rc::clone(&x);
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub CLONE_ON_REF_PTR,
restriction,
"using 'clone' on a ref-counted pointer"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `.clone()` on an `&&T`.
+ /// ### What it does
+ /// Checks for usage of `.clone()` on an `&&T`.
///
- /// **Why is this bad?** Cloning an `&&T` copies the inner `&T`, instead of
+ /// ### Why is this bad?
+ /// Cloning an `&&T` copies the inner `&T`, instead of
/// cloning the underlying `T`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// fn main() {
/// let x = vec![1];
/// println!("{:p} {:p}", *y, z); // prints out the same pointer
/// }
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub CLONE_DOUBLE_REF,
correctness,
"using `clone` on `&&T`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `.to_string()` on an `&&T` where
+ /// ### What it does
+ /// Checks for usage of `.to_string()` on an `&&T` where
/// `T` implements `ToString` directly (like `&&str` or `&&String`).
///
- /// **Why is this bad?** This bypasses the specialized implementation of
+ /// ### Why is this bad?
+ /// This bypasses the specialized implementation of
/// `ToString` and instead goes through the more expensive string formatting
/// facilities.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// // Generic implementation for `T: Display` is used (slow)
/// ["foo", "bar"].iter().map(|s| s.to_string());
/// // OK, the specialized impl is used
/// ["foo", "bar"].iter().map(|&s| s.to_string());
/// ```
+ #[clippy::version = "1.40.0"]
pub INEFFICIENT_TO_STRING,
pedantic,
"using `to_string` on `&&T` where `T: ToString`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for `new` not returning a type that contains `Self`.
+ /// ### What it does
+ /// Checks for `new` not returning a type that contains `Self`.
///
- /// **Why is this bad?** As a convention, `new` methods are used to make a new
+ /// ### Why is this bad?
+ /// As a convention, `new` methods are used to make a new
/// instance of a type.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// In an impl block:
/// ```rust
/// # struct Foo;
/// fn new() -> Self;
/// }
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub NEW_RET_NO_SELF,
style,
"not returning type containing `Self` in a `new` method"
}
declare_clippy_lint! {
- /// **What it does:** Checks for string methods that receive a single-character
+ /// ### What it does
+ /// Checks for string methods that receive a single-character
/// `str` as an argument, e.g., `_.split("x")`.
///
- /// **Why is this bad?** Performing these methods using a `char` is faster than
+ /// ### Why is this bad?
+ /// Performing these methods using a `char` is faster than
/// using a `str`.
///
- /// **Known problems:** Does not catch multi-byte unicode characters.
+ /// ### Known problems
+ /// Does not catch multi-byte unicode characters.
///
- /// **Example:**
+ /// ### Example
/// ```rust,ignore
/// // Bad
/// _.split("x");
///
/// // Good
/// _.split('x');
+ #[clippy::version = "pre 1.29.0"]
pub SINGLE_CHAR_PATTERN,
perf,
"using a single-character str where a char could be used, e.g., `_.split(\"x\")`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for calling `.step_by(0)` on iterators which panics.
+ /// ### What it does
+ /// Checks for calling `.step_by(0)` on iterators which panics.
///
- /// **Why is this bad?** This very much looks like an oversight. Use `panic!()` instead if you
+ /// ### Why is this bad?
+ /// This very much looks like an oversight. Use `panic!()` instead if you
/// actually intend to panic.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust,should_panic
/// for x in (0..100).step_by(0) {
/// //..
/// }
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub ITERATOR_STEP_BY_ZERO,
correctness,
"using `Iterator::step_by(0)`, which will panic at runtime"
}
declare_clippy_lint! {
- /// **What it does:** Checks for indirect collection of populated `Option`
+ /// ### What it does
+ /// Checks for indirect collection of populated `Option`
///
- /// **Why is this bad?** `Option` is like a collection of 0-1 things, so `flatten`
+ /// ### Why is this bad?
+ /// `Option` is like a collection of 0-1 things, so `flatten`
/// automatically does this without suspicious-looking `unwrap` calls.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// let _ = std::iter::empty::<Option<i32>>().filter(Option::is_some).map(Option::unwrap);
/// ```
/// ```rust
/// let _ = std::iter::empty::<Option<i32>>().flatten();
/// ```
+ #[clippy::version = "1.53.0"]
pub OPTION_FILTER_MAP,
complexity,
"filtering `Option` for `Some` then force-unwrapping, which can be one type-safe operation"
}
declare_clippy_lint! {
- /// **What it does:** Checks for the use of `iter.nth(0)`.
+ /// ### What it does
+ /// Checks for the use of `iter.nth(0)`.
///
- /// **Why is this bad?** `iter.next()` is equivalent to
+ /// ### Why is this bad?
+ /// `iter.next()` is equivalent to
/// `iter.nth(0)`, as they both consume the next element,
/// but is more readable.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// # use std::collections::HashSet;
/// // Bad
/// # s.insert(1);
/// let x = s.iter().next();
/// ```
+ #[clippy::version = "1.42.0"]
pub ITER_NTH_ZERO,
style,
"replace `iter.nth(0)` with `iter.next()`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for use of `.iter().nth()` (and the related
- /// `.iter_mut().nth()`) on standard library types with O(1) element access.
+ /// ### What it does
+ /// Checks for use of `.iter().nth()` (and the related
+ /// `.iter_mut().nth()`) on standard library types with *O*(1) element access.
///
- /// **Why is this bad?** `.get()` and `.get_mut()` are more efficient and more
+ /// ### Why is this bad?
+ /// `.get()` and `.get_mut()` are more efficient and more
/// readable.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let some_vec = vec![0, 1, 2, 3];
/// let bad_vec = some_vec.iter().nth(3);
/// let bad_vec = some_vec.get(3);
/// let bad_slice = &some_vec[..].get(3);
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub ITER_NTH,
perf,
"using `.iter().nth()` on a standard library type with O(1) element access"
}
declare_clippy_lint! {
- /// **What it does:** Checks for use of `.skip(x).next()` on iterators.
- ///
- /// **Why is this bad?** `.nth(x)` is cleaner
+ /// ### What it does
+ /// Checks for use of `.skip(x).next()` on iterators.
///
- /// **Known problems:** None.
+ /// ### Why is this bad?
+ /// `.nth(x)` is cleaner
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let some_vec = vec![0, 1, 2, 3];
/// let bad_vec = some_vec.iter().skip(3).next();
/// let bad_vec = some_vec.iter().nth(3);
/// let bad_slice = &some_vec[..].iter().nth(3);
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub ITER_SKIP_NEXT,
style,
"using `.skip(x).next()` on an iterator"
}
declare_clippy_lint! {
- /// **What it does:** Checks for use of `.get().unwrap()` (or
+ /// ### What it does
+ /// Checks for use of `.get().unwrap()` (or
/// `.get_mut().unwrap`) on a standard library type which implements `Index`
///
- /// **Why is this bad?** Using the Index trait (`[]`) is more clear and more
+ /// ### Why is this bad?
+ /// Using the Index trait (`[]`) is more clear and more
/// concise.
///
- /// **Known problems:** Not a replacement for error handling: Using either
+ /// ### Known problems
+ /// Not a replacement for error handling: Using either
/// `.unwrap()` or the Index trait (`[]`) carries the risk of causing a `panic`
/// if the value being accessed is `None`. If the use of `.get().unwrap()` is a
/// temporary placeholder for dealing with the `Option` type, then this does
/// is handled in a future refactor instead of using `.unwrap()` or the Index
/// trait.
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let mut some_vec = vec![0, 1, 2, 3];
/// let last = some_vec.get(3).unwrap();
/// let last = some_vec[3];
/// some_vec[0] = 1;
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub GET_UNWRAP,
restriction,
"using `.get().unwrap()` or `.get_mut().unwrap()` when using `[]` would work instead"
}
declare_clippy_lint! {
- /// **What it does:** Checks for the use of `.extend(s.chars())` where s is a
- /// `&str` or `String`.
+ /// ### What it does
+ /// Checks for occurrences where one vector gets extended instead of append
+ ///
+ /// ### Why is this bad?
+ /// Using `append` instead of `extend` is more concise and faster
+ ///
+ /// ### Example
+ /// ```rust
+ /// let mut a = vec![1, 2, 3];
+ /// let mut b = vec![4, 5, 6];
+ ///
+ /// // Bad
+ /// a.extend(b.drain(..));
///
- /// **Why is this bad?** `.push_str(s)` is clearer
+ /// // Good
+ /// a.append(&mut b);
+ /// ```
+ #[clippy::version = "1.55.0"]
+ pub EXTEND_WITH_DRAIN,
+ perf,
+ "using vec.append(&mut vec) to move the full range of a vecor to another"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the use of `.extend(s.chars())` where s is a
+ /// `&str` or `String`.
///
- /// **Known problems:** None.
+ /// ### Why is this bad?
+ /// `.push_str(s)` is clearer
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let abc = "abc";
/// let def = String::from("def");
/// s.push_str(abc);
/// s.push_str(&def);
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub STRING_EXTEND_CHARS,
style,
"using `x.extend(s.chars())` where s is a `&str` or `String`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for the use of `.cloned().collect()` on slice to
+ /// ### What it does
+ /// Checks for the use of `.cloned().collect()` on slice to
/// create a `Vec`.
///
- /// **Why is this bad?** `.to_vec()` is clearer
- ///
- /// **Known problems:** None.
+ /// ### Why is this bad?
+ /// `.to_vec()` is clearer
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let s = [1, 2, 3, 4, 5];
/// let s2: Vec<isize> = s[..].iter().cloned().collect();
/// let s = [1, 2, 3, 4, 5];
/// let s2: Vec<isize> = s.to_vec();
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub ITER_CLONED_COLLECT,
style,
"using `.cloned().collect()` on slice to create a `Vec`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.chars().last()` or
+ /// ### What it does
+ /// Checks for usage of `_.chars().last()` or
/// `_.chars().next_back()` on a `str` to check if it ends with a given char.
///
- /// **Why is this bad?** Readability, this can be written more concisely as
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
/// `_.ends_with(_)`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let name = "_";
///
/// // Good
/// name.ends_with('_') || name.ends_with('-');
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub CHARS_LAST_CMP,
style,
"using `.chars().last()` or `.chars().next_back()` to check if a string ends with a char"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `.as_ref()` or `.as_mut()` where the
+ /// ### What it does
+ /// Checks for usage of `.as_ref()` or `.as_mut()` where the
/// types before and after the call are the same.
///
- /// **Why is this bad?** The call is unnecessary.
- ///
- /// **Known problems:** None.
+ /// ### Why is this bad?
+ /// The call is unnecessary.
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # fn do_stuff(x: &[i32]) {}
/// let x: &[i32] = &[1, 2, 3, 4, 5];
/// let x: &[i32] = &[1, 2, 3, 4, 5];
/// do_stuff(x);
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub USELESS_ASREF,
complexity,
"using `as_ref` where the types before and after the call are the same"
}
declare_clippy_lint! {
- /// **What it does:** Checks for using `fold` when a more succinct alternative exists.
+ /// ### What it does
+ /// Checks for using `fold` when a more succinct alternative exists.
/// Specifically, this checks for `fold`s which could be replaced by `any`, `all`,
/// `sum` or `product`.
///
- /// **Why is this bad?** Readability.
+ /// ### Why is this bad?
+ /// Readability.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let _ = (0..3).fold(false, |acc, x| acc || x > 2);
/// ```
/// ```rust
/// let _ = (0..3).any(|x| x > 2);
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub UNNECESSARY_FOLD,
style,
"using `fold` when a more succinct alternative exists"
}
declare_clippy_lint! {
- /// **What it does:** Checks for `filter_map` calls which could be replaced by `filter` or `map`.
+ /// ### What it does
+ /// Checks for `filter_map` calls which could be replaced by `filter` or `map`.
/// More specifically it checks if the closure provided is only performing one of the
/// filter or map operations and suggests the appropriate option.
///
- /// **Why is this bad?** Complexity. The intent is also clearer if only a single
+ /// ### Why is this bad?
+ /// Complexity. The intent is also clearer if only a single
/// operation is being performed.
///
- /// **Known problems:** None
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let _ = (0..3).filter_map(|x| if x > 2 { Some(x) } else { None });
///
/// // As there is no conditional check on the argument this could be written as:
/// let _ = (0..4).map(|x| x + 1);
/// ```
+ #[clippy::version = "1.31.0"]
pub UNNECESSARY_FILTER_MAP,
complexity,
"using `filter_map` when a more succinct alternative exists"
}
declare_clippy_lint! {
- /// **What it does:** Checks for `into_iter` calls on references which should be replaced by `iter`
+ /// ### What it does
+ /// Checks for `into_iter` calls on references which should be replaced by `iter`
/// or `iter_mut`.
///
- /// **Why is this bad?** Readability. Calling `into_iter` on a reference will not move out its
+ /// ### Why is this bad?
+ /// Readability. Calling `into_iter` on a reference will not move out its
/// content into the resulting iterator, which is confusing. It is better just call `iter` or
/// `iter_mut` directly.
///
- /// **Known problems:** None
- ///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// // Bad
/// let _ = (&vec![3, 4, 5]).into_iter();
/// // Good
/// let _ = (&vec![3, 4, 5]).iter();
/// ```
+ #[clippy::version = "1.32.0"]
pub INTO_ITER_ON_REF,
style,
"using `.into_iter()` on a reference"
}
declare_clippy_lint! {
- /// **What it does:** Checks for calls to `map` followed by a `count`.
- ///
- /// **Why is this bad?** It looks suspicious. Maybe `map` was confused with `filter`.
- /// If the `map` call is intentional, this should be rewritten. Or, if you intend to
- /// drive the iterator to completion, you can just use `for_each` instead.
- ///
- /// **Known problems:** None
+ /// ### What it does
+ /// Checks for calls to `map` followed by a `count`.
///
- /// **Example:**
+ /// ### Why is this bad?
+ /// It looks suspicious. Maybe `map` was confused with `filter`.
+ /// If the `map` call is intentional, this should be rewritten
+ /// using `inspect`. Or, if you intend to drive the iterator to
+ /// completion, you can just use `for_each` instead.
///
+ /// ### Example
/// ```rust
/// let _ = (0..3).map(|x| x + 2).count();
/// ```
+ #[clippy::version = "1.39.0"]
pub SUSPICIOUS_MAP,
- complexity,
+ suspicious,
"suspicious usage of map"
}
declare_clippy_lint! {
- /// **What it does:** Checks for `MaybeUninit::uninit().assume_init()`.
+ /// ### What it does
+ /// Checks for `MaybeUninit::uninit().assume_init()`.
///
- /// **Why is this bad?** For most types, this is undefined behavior.
+ /// ### Why is this bad?
+ /// For most types, this is undefined behavior.
///
- /// **Known problems:** For now, we accept empty tuples and tuples / arrays
+ /// ### Known problems
+ /// For now, we accept empty tuples and tuples / arrays
/// of `MaybeUninit`. There may be other types that allow uninitialized
/// data, but those are not yet rigorously defined.
///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// // Beware the UB
/// use std::mem::MaybeUninit;
/// MaybeUninit::uninit().assume_init()
/// };
/// ```
+ #[clippy::version = "1.39.0"]
pub UNINIT_ASSUMED_INIT,
correctness,
"`MaybeUninit::uninit().assume_init()`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for `.checked_add/sub(x).unwrap_or(MAX/MIN)`.
- ///
- /// **Why is this bad?** These can be written simply with `saturating_add/sub` methods.
+ /// ### What it does
+ /// Checks for `.checked_add/sub(x).unwrap_or(MAX/MIN)`.
///
- /// **Example:**
+ /// ### Why is this bad?
+ /// These can be written simply with `saturating_add/sub` methods.
///
+ /// ### Example
/// ```rust
/// # let y: u32 = 0;
/// # let x: u32 = 100;
/// let add = x.saturating_add(y);
/// let sub = x.saturating_sub(y);
/// ```
+ #[clippy::version = "1.39.0"]
pub MANUAL_SATURATING_ARITHMETIC,
style,
"`.chcked_add/sub(x).unwrap_or(MAX/MIN)`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for `offset(_)`, `wrapping_`{`add`, `sub`}, etc. on raw pointers to
+ /// ### What it does
+ /// Checks for `offset(_)`, `wrapping_`{`add`, `sub`}, etc. on raw pointers to
/// zero-sized types
///
- /// **Why is this bad?** This is a no-op, and likely unintended
+ /// ### Why is this bad?
+ /// This is a no-op, and likely unintended
///
- /// **Known problems:** None
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// unsafe { (&() as *const ()).offset(1) };
/// ```
+ #[clippy::version = "1.41.0"]
pub ZST_OFFSET,
correctness,
"Check for offset calculations on raw pointers to zero-sized types"
}
declare_clippy_lint! {
- /// **What it does:** Checks for `FileType::is_file()`.
+ /// ### What it does
+ /// Checks for `FileType::is_file()`.
///
- /// **Why is this bad?** When people testing a file type with `FileType::is_file`
+ /// ### Why is this bad?
+ /// When people testing a file type with `FileType::is_file`
/// they are testing whether a path is something they can get bytes from. But
/// `is_file` doesn't cover special file types in unix-like systems, and doesn't cover
/// symlink in windows. Using `!FileType::is_dir()` is a better way to that intention.
///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// # || {
/// let metadata = std::fs::metadata("foo.txt")?;
/// # Ok::<_, std::io::Error>(())
/// # };
/// ```
+ #[clippy::version = "1.42.0"]
pub FILETYPE_IS_FILE,
restriction,
"`FileType::is_file` is not recommended to test for readable file type"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.as_ref().map(Deref::deref)` or it's aliases (such as String::as_str).
+ /// ### What it does
+ /// Checks for usage of `_.as_ref().map(Deref::deref)` or it's aliases (such as String::as_str).
///
- /// **Why is this bad?** Readability, this can be written more concisely as
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely as
/// `_.as_deref()`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let opt = Some("".to_string());
/// opt.as_ref().map(String::as_str)
/// opt.as_deref()
/// # ;
/// ```
+ #[clippy::version = "1.42.0"]
pub OPTION_AS_REF_DEREF,
complexity,
"using `as_ref().map(Deref::deref)`, which is more succinctly expressed as `as_deref()`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `iter().next()` on a Slice or an Array
- ///
- /// **Why is this bad?** These can be shortened into `.get()`
+ /// ### What it does
+ /// Checks for usage of `iter().next()` on a Slice or an Array
///
- /// **Known problems:** None.
+ /// ### Why is this bad?
+ /// These can be shortened into `.get()`
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let a = [1, 2, 3];
/// # let b = vec![1, 2, 3];
/// a.get(2);
/// b.get(0);
/// ```
+ #[clippy::version = "1.46.0"]
pub ITER_NEXT_SLICE,
style,
"using `.iter().next()` on a sliced array, which can be shortened to just `.get()`"
}
declare_clippy_lint! {
- /// **What it does:** Warns when using `push_str`/`insert_str` with a single-character string literal
+ /// ### What it does
+ /// Warns when using `push_str`/`insert_str` with a single-character string literal
/// where `push`/`insert` with a `char` would work fine.
///
- /// **Why is this bad?** It's less clear that we are pushing a single character.
+ /// ### Why is this bad?
+ /// It's less clear that we are pushing a single character.
///
- /// **Known problems:** None
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let mut string = String::new();
/// string.insert_str(0, "R");
/// string.insert(0, 'R');
/// string.push('R');
/// ```
+ #[clippy::version = "1.49.0"]
pub SINGLE_CHAR_ADD_STR,
style,
"`push_str()` or `insert_str()` used with a single-character string literal as parameter"
}
declare_clippy_lint! {
- /// **What it does:** As the counterpart to `or_fun_call`, this lint looks for unnecessary
+ /// ### What it does
+ /// As the counterpart to `or_fun_call`, this lint looks for unnecessary
/// lazily evaluated closures on `Option` and `Result`.
///
/// This lint suggests changing the following functions, when eager evaluation results in
/// - `get_or_insert_with` to `get_or_insert`
/// - `ok_or_else` to `ok_or`
///
- /// **Why is this bad?** Using eager evaluation is shorter and simpler in some cases.
+ /// ### Why is this bad?
+ /// Using eager evaluation is shorter and simpler in some cases.
///
- /// **Known problems:** It is possible, but not recommended for `Deref` and `Index` to have
+ /// ### Known problems
+ /// It is possible, but not recommended for `Deref` and `Index` to have
/// side effects. Eagerly evaluating them can change the semantics of the program.
///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// // example code where clippy issues a warning
/// let opt: Option<u32> = None;
///
/// opt.unwrap_or(42);
/// ```
+ #[clippy::version = "1.48.0"]
pub UNNECESSARY_LAZY_EVALUATIONS,
style,
"using unnecessary lazy evaluation, which can be replaced with simpler eager evaluation"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `_.map(_).collect::<Result<(), _>()`.
+ /// ### What it does
+ /// Checks for usage of `_.map(_).collect::<Result<(), _>()`.
///
- /// **Why is this bad?** Using `try_for_each` instead is more readable and idiomatic.
- ///
- /// **Known problems:** None
- ///
- /// **Example:**
+ /// ### Why is this bad?
+ /// Using `try_for_each` instead is more readable and idiomatic.
///
+ /// ### Example
/// ```rust
/// (0..3).map(|t| Err(t)).collect::<Result<(), _>>();
/// ```
/// ```rust
/// (0..3).try_for_each(|t| Err(t));
/// ```
+ #[clippy::version = "1.49.0"]
pub MAP_COLLECT_RESULT_UNIT,
style,
"using `.map(_).collect::<Result<(),_>()`, which can be replaced with `try_for_each`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for `from_iter()` function calls on types that implement the `FromIterator`
+ /// ### What it does
+ /// Checks for `from_iter()` function calls on types that implement the `FromIterator`
/// trait.
///
- /// **Why is this bad?** It is recommended style to use collect. See
+ /// ### Why is this bad?
+ /// It is recommended style to use collect. See
/// [FromIterator documentation](https://doc.rust-lang.org/std/iter/trait.FromIterator.html)
///
- /// **Known problems:** None.
- ///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// use std::iter::FromIterator;
///
///
/// assert_eq!(v, vec![5, 5, 5, 5, 5]);
/// ```
+ #[clippy::version = "1.49.0"]
pub FROM_ITER_INSTEAD_OF_COLLECT,
- style,
+ pedantic,
"use `.collect()` instead of `::from_iter()`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `inspect().for_each()`.
+ /// ### What it does
+ /// Checks for usage of `inspect().for_each()`.
///
- /// **Why is this bad?** It is the same as performing the computation
+ /// ### Why is this bad?
+ /// It is the same as performing the computation
/// inside `inspect` at the beginning of the closure in `for_each`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// [1,2,3,4,5].iter()
/// .inspect(|&x| println!("inspect the number: {}", x))
/// assert!(x >= 0);
/// });
/// ```
+ #[clippy::version = "1.51.0"]
pub INSPECT_FOR_EACH,
complexity,
"using `.inspect().for_each()`, which can be replaced with `.for_each()`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `filter_map(|x| x)`.
+ /// ### What it does
+ /// Checks for usage of `filter_map(|x| x)`.
///
- /// **Why is this bad?** Readability, this can be written more concisely by using `flatten`.
- ///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely by using `flatten`.
///
+ /// ### Example
/// ```rust
/// # let iter = vec![Some(1)].into_iter();
/// iter.filter_map(|x| x);
/// # let iter = vec![Some(1)].into_iter();
/// iter.flatten();
/// ```
+ #[clippy::version = "1.52.0"]
pub FILTER_MAP_IDENTITY,
complexity,
"call to `filter_map` where `flatten` is sufficient"
}
declare_clippy_lint! {
- /// **What it does:** Checks for the use of `.bytes().nth()`.
+ /// ### What it does
+ /// Checks for instances of `map(f)` where `f` is the identity function.
///
- /// **Why is this bad?** `.as_bytes().get()` is more efficient and more
- /// readable.
+ /// ### Why is this bad?
+ /// It can be written more concisely without the call to `map`.
///
- /// **Known problems:** None.
+ /// ### Example
+ /// ```rust
+ /// let x = [1, 2, 3];
+ /// let y: Vec<_> = x.iter().map(|x| x).map(|x| 2*x).collect();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let x = [1, 2, 3];
+ /// let y: Vec<_> = x.iter().map(|x| 2*x).collect();
+ /// ```
+ #[clippy::version = "1.52.0"]
+ pub MAP_IDENTITY,
+ complexity,
+ "using iterator.map(|x| x)"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for the use of `.bytes().nth()`.
///
- /// **Example:**
+ /// ### Why is this bad?
+ /// `.as_bytes().get()` is more efficient and more
+ /// readable.
///
+ /// ### Example
/// ```rust
/// // Bad
/// let _ = "Hello".bytes().nth(3);
/// // Good
/// let _ = "Hello".as_bytes().get(3);
/// ```
+ #[clippy::version = "1.52.0"]
pub BYTES_NTH,
style,
"replace `.bytes().nth()` with `.as_bytes().get()`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for the usage of `_.to_owned()`, `vec.to_vec()`, or similar when calling `_.clone()` would be clearer.
+ /// ### What it does
+ /// Checks for the usage of `_.to_owned()`, `vec.to_vec()`, or similar when calling `_.clone()` would be clearer.
///
- /// **Why is this bad?** These methods do the same thing as `_.clone()` but may be confusing as
+ /// ### Why is this bad?
+ /// These methods do the same thing as `_.clone()` but may be confusing as
/// to why we are calling `to_vec` on something that is already a `Vec` or calling `to_owned` on something that is already owned.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// let a = vec![1, 2, 3];
/// let b = a.to_vec();
/// let b = a.clone();
/// let c = a.clone();
/// ```
+ #[clippy::version = "1.52.0"]
pub IMPLICIT_CLONE,
pedantic,
"implicitly cloning a value by invoking a function on its dereferenced type"
}
declare_clippy_lint! {
- /// **What it does:** Checks for the use of `.iter().count()`.
+ /// ### What it does
+ /// Checks for the use of `.iter().count()`.
///
- /// **Why is this bad?** `.len()` is more efficient and more
+ /// ### Why is this bad?
+ /// `.len()` is more efficient and more
/// readable.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// // Bad
/// let some_vec = vec![0, 1, 2, 3];
/// let _ = some_vec.len();
/// let _ = &some_vec[..].len();
/// ```
+ #[clippy::version = "1.52.0"]
pub ITER_COUNT,
complexity,
"replace `.iter().count()` with `.len()`"
}
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calls to [`splitn`]
+ /// (https://doc.rust-lang.org/std/primitive.str.html#method.splitn) and
+ /// related functions with either zero or one splits.
+ ///
+ /// ### Why is this bad?
+ /// These calls don't actually split the value and are
+ /// likely to be intended as a different number.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// let s = "";
+ /// for x in s.splitn(1, ":") {
+ /// // use x
+ /// }
+ ///
+ /// // Good
+ /// let s = "";
+ /// for x in s.splitn(2, ":") {
+ /// // use x
+ /// }
+ /// ```
+ #[clippy::version = "1.54.0"]
+ pub SUSPICIOUS_SPLITN,
+ correctness,
+ "checks for `.splitn(0, ..)` and `.splitn(1, ..)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for manual implementations of `str::repeat`
+ ///
+ /// ### Why is this bad?
+ /// These are both harder to read, as well as less performant.
+ ///
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// let x: String = std::iter::repeat('x').take(10).collect();
+ ///
+ /// // Good
+ /// let x: String = "x".repeat(10);
+ /// ```
+ #[clippy::version = "1.54.0"]
+ pub MANUAL_STR_REPEAT,
+ perf,
+ "manual implementation of `str::repeat`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usages of `str::splitn(2, _)`
+ ///
+ /// ### Why is this bad?
+ /// `split_once` is both clearer in intent and slightly more efficient.
+ ///
+ /// ### Example
+ /// ```rust,ignore
+ /// // Bad
+ /// let (key, value) = _.splitn(2, '=').next_tuple()?;
+ /// let value = _.splitn(2, '=').nth(1)?;
+ ///
+ /// // Good
+ /// let (key, value) = _.split_once('=')?;
+ /// let value = _.split_once('=')?.1;
+ /// ```
+ #[clippy::version = "1.57.0"]
+ pub MANUAL_SPLIT_ONCE,
+ complexity,
+ "replace `.splitn(2, pat)` with `.split_once(pat)`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usages of `str::splitn` (or `str::rsplitn`) where using `str::split` would be the same.
+ /// ### Why is this bad?
+ /// The function `split` is simpler and there is no performance difference in these cases, considering
+ /// that both functions return a lazy iterator.
+ /// ### Example
+ /// ```rust
+ /// // Bad
+ /// let str = "key=value=add";
+ /// let _ = str.splitn(3, '=').next().unwrap();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// // Good
+ /// let str = "key=value=add";
+ /// let _ = str.split('=').next().unwrap();
+ /// ```
+ #[clippy::version = "1.58.0"]
+ pub NEEDLESS_SPLITN,
+ complexity,
+ "usages of `str::splitn` that can be replaced with `str::split`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for unnecessary calls to [`ToOwned::to_owned`](https://doc.rust-lang.org/std/borrow/trait.ToOwned.html#tymethod.to_owned)
+ /// and other `to_owned`-like functions.
+ ///
+ /// ### Why is this bad?
+ /// The unnecessary calls result in useless allocations.
+ ///
+ /// ### Known problems
+ /// `unnecessary_to_owned` can falsely trigger if `IntoIterator::into_iter` is applied to an
+ /// owned copy of a resource and the resource is later used mutably. See
+ /// [#8148](https://github.com/rust-lang/rust-clippy/issues/8148).
+ ///
+ /// ### Example
+ /// ```rust
+ /// let path = std::path::Path::new("x");
+ /// foo(&path.to_string_lossy().to_string());
+ /// fn foo(s: &str) {}
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let path = std::path::Path::new("x");
+ /// foo(&path.to_string_lossy());
+ /// fn foo(s: &str) {}
+ /// ```
+ #[clippy::version = "1.58.0"]
+ pub UNNECESSARY_TO_OWNED,
+ perf,
+ "unnecessary calls to `to_owned`-like functions"
+}
+
pub struct Methods {
+ avoid_breaking_exported_api: bool,
msrv: Option<RustcVersion>,
}
impl Methods {
#[must_use]
- pub fn new(msrv: Option<RustcVersion>) -> Self {
- Self { msrv }
+ pub fn new(avoid_breaking_exported_api: bool, msrv: Option<RustcVersion>) -> Self {
+ Self {
+ avoid_breaking_exported_api,
+ msrv,
+ }
}
}
EXPECT_USED,
SHOULD_IMPLEMENT_TRAIT,
WRONG_SELF_CONVENTION,
- WRONG_PUB_SELF_CONVENTION,
OK_EXPECT,
+ UNWRAP_OR_ELSE_DEFAULT,
MAP_UNWRAP_OR,
RESULT_MAP_OR_INTO_OPTION,
OPTION_MAP_OR_NONE,
CLONE_ON_COPY,
CLONE_ON_REF_PTR,
CLONE_DOUBLE_REF,
+ ITER_OVEREAGER_CLONED,
+ CLONED_INSTEAD_OF_COPIED,
+ FLAT_MAP_OPTION,
INEFFICIENT_TO_STRING,
NEW_RET_NO_SELF,
SINGLE_CHAR_PATTERN,
SEARCH_IS_SOME,
FILTER_NEXT,
SKIP_WHILE_NEXT,
- FILTER_MAP,
FILTER_MAP_IDENTITY,
+ MAP_IDENTITY,
MANUAL_FILTER_MAP,
MANUAL_FIND_MAP,
OPTION_FILTER_MAP,
MAP_COLLECT_RESULT_UNIT,
FROM_ITER_INSTEAD_OF_COLLECT,
INSPECT_FOR_EACH,
- IMPLICIT_CLONE
+ IMPLICIT_CLONE,
+ SUSPICIOUS_SPLITN,
+ MANUAL_STR_REPEAT,
+ EXTEND_WITH_DRAIN,
+ MANUAL_SPLIT_ONCE,
+ NEEDLESS_SPLITN,
+ UNNECESSARY_TO_OWNED,
]);
/// Extracts a method call name, args, and `Span` of the method name.
-fn method_call<'tcx>(recv: &'tcx hir::Expr<'tcx>) -> Option<(SymbolStr, &'tcx [hir::Expr<'tcx>], Span)> {
- if let ExprKind::MethodCall(path, span, args, _) = recv.kind {
+fn method_call<'tcx>(recv: &'tcx hir::Expr<'tcx>) -> Option<(&'tcx str, &'tcx [hir::Expr<'tcx>], Span)> {
+ if let ExprKind::MethodCall(path, args, _) = recv.kind {
if !args.iter().any(|e| e.span.from_expansion()) {
- return Some((path.ident.name.as_str(), args, span));
+ let name = path.ident.name.as_str();
+ return Some((name, args, path.ident.span));
}
}
None
}
-/// Same as `method_call` but the `SymbolStr` is dereferenced into a temporary `&str`
-macro_rules! method_call {
- ($expr:expr) => {
- method_call($expr)
- .as_ref()
- .map(|&(ref name, args, span)| (&**name, args, span))
- };
-}
-
impl<'tcx> LateLintPass<'tcx> for Methods {
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
- if in_macro(expr.span) {
+ if expr.span.from_expansion() {
return;
}
match expr.kind {
hir::ExprKind::Call(func, args) => {
- from_iter_instead_of_collect::check(cx, expr, args, &func.kind);
+ from_iter_instead_of_collect::check(cx, expr, args, func);
},
- hir::ExprKind::MethodCall(method_call, ref method_span, args, _) => {
- or_fun_call::check(cx, expr, *method_span, &method_call.ident.as_str(), args);
- expect_fun_call::check(cx, expr, *method_span, &method_call.ident.as_str(), args);
+ hir::ExprKind::MethodCall(method_call, args, _) => {
+ let method_span = method_call.ident.span;
+ or_fun_call::check(cx, expr, method_span, method_call.ident.as_str(), args);
+ expect_fun_call::check(cx, expr, method_span, method_call.ident.as_str(), args);
clone_on_copy::check(cx, expr, method_call.ident.name, args);
clone_on_ref_ptr::check(cx, expr, method_call.ident.name, args);
inefficient_to_string::check(cx, expr, method_call.ident.name, args);
single_char_add_str::check(cx, expr, args);
- into_iter_on_ref::check(cx, expr, *method_span, method_call.ident.name, args);
+ into_iter_on_ref::check(cx, expr, method_span, method_call.ident.name, args);
single_char_pattern::check(cx, expr, method_call.ident.name, args);
+ unnecessary_to_owned::check(cx, expr, method_call.ident.name, args);
},
hir::ExprKind::Binary(op, lhs, rhs) if op.node == hir::BinOpKind::Eq || op.node == hir::BinOpKind::Ne => {
let mut info = BinaryExprInfo {
then {
// if this impl block implements a trait, lint in trait definition instead
- if !implements_trait && cx.access_levels.is_exported(impl_item.hir_id()) {
+ if !implements_trait && cx.access_levels.is_exported(impl_item.def_id) {
// check missing trait implementations
for method_config in &TRAIT_METHODS {
if name == method_config.method_name &&
}
}
- wrong_self_convention::check(
- cx,
- &name,
- item.vis.node.is_pub(),
- self_ty,
- first_arg_ty,
- first_arg.pat.span,
- implements_trait,
- false
- );
+ if sig.decl.implicit_self.has_implicit_self()
+ && !(self.avoid_breaking_exported_api
+ && cx.access_levels.is_exported(impl_item.def_id))
+ {
+ wrong_self_convention::check(
+ cx,
+ name,
+ self_ty,
+ first_arg_ty,
+ first_arg.pat.span,
+ implements_trait,
+ false
+ );
+ }
}
}
// one of the associated types must be Self
for &(predicate, _span) in cx.tcx.explicit_item_bounds(def_id) {
if let ty::PredicateKind::Projection(projection_predicate) = predicate.kind().skip_binder() {
+ let assoc_ty = match projection_predicate.term {
+ ty::Term::Ty(ty) => ty,
+ ty::Term::Const(_c) => continue,
+ };
// walk the associated type and check for Self
if let Some(self_adt) = self_ty.ty_adt_def() {
- if contains_adt_constructor(projection_predicate.ty, self_adt) {
+ if contains_adt_constructor(assoc_ty, self_adt) {
return;
}
- } else if contains_ty(projection_predicate.ty, self_ty) {
+ } else if contains_ty(assoc_ty, self_ty) {
return;
}
}
}
}
- if name == "new" && !TyS::same_type(ret_ty, self_ty) {
+ if name == "new" && ret_ty != self_ty {
span_lint(
cx,
NEW_RET_NO_SELF,
if_chain! {
if let TraitItemKind::Fn(ref sig, _) = item.kind;
+ if sig.decl.implicit_self.has_implicit_self();
if let Some(first_arg_ty) = sig.decl.inputs.iter().next();
+
then {
let first_arg_span = first_arg_ty.span;
let first_arg_ty = hir_ty_to_ty(cx.tcx, first_arg_ty);
- let self_ty = TraitRef::identity(cx.tcx, item.def_id.to_def_id()).self_ty();
+ let self_ty = TraitRef::identity(cx.tcx, item.def_id.to_def_id()).self_ty().skip_binder();
wrong_self_convention::check(
cx,
- &item.ident.name.as_str(),
- false,
+ item.ident.name.as_str(),
self_ty,
first_arg_ty,
first_arg_span,
if item.ident.name == sym::new;
if let TraitItemKind::Fn(_, _) = item.kind;
let ret_ty = return_ty(cx, item.hir_id());
- let self_ty = TraitRef::identity(cx.tcx, item.def_id.to_def_id()).self_ty();
+ let self_ty = TraitRef::identity(cx.tcx, item.def_id.to_def_id()).self_ty().skip_binder();
if !contains_ty(ret_ty, self_ty);
then {
#[allow(clippy::too_many_lines)]
fn check_methods<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, msrv: Option<&RustcVersion>) {
- if let Some((name, [recv, args @ ..], span)) = method_call!(expr) {
+ if let Some((name, [recv, args @ ..], span)) = method_call(expr) {
match (name, args) {
- ("add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub", [recv, _]) => {
- zst_offset::check(cx, expr, recv)
+ ("add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub", [_arg]) => {
+ zst_offset::check(cx, expr, recv);
},
("and_then", [arg]) => {
let biom_option_linted = bind_instead_of_map::OptionAndThenSome::check(cx, expr, recv, arg);
("as_mut", []) => useless_asref::check(cx, expr, "as_mut", recv),
("as_ref", []) => useless_asref::check(cx, expr, "as_ref", recv),
("assume_init", []) => uninit_assumed_init::check(cx, expr, recv),
- ("collect", []) => match method_call!(recv) {
- Some(("cloned", [recv2], _)) => iter_cloned_collect::check(cx, expr, recv2),
+ ("cloned", []) => cloned_instead_of_copied::check(cx, expr, recv, span, msrv),
+ ("collect", []) => match method_call(recv) {
+ Some((name @ ("cloned" | "copied"), [recv2], _)) => {
+ iter_cloned_collect::check(cx, name, expr, recv2);
+ },
Some(("map", [m_recv, m_arg], _)) => {
map_collect_result_unit::check(cx, expr, m_recv, m_arg, recv);
},
+ Some(("take", [take_self_arg, take_arg], _)) => {
+ if meets_msrv(msrv, &msrvs::STR_REPEAT) {
+ manual_str_repeat::check(cx, expr, recv, take_self_arg, take_arg);
+ }
+ },
_ => {},
},
- ("count", []) => match method_call!(recv) {
- Some((name @ ("into_iter" | "iter" | "iter_mut"), [recv2], _)) => {
- iter_count::check(cx, expr, recv2, name);
+ (name @ "count", args @ []) => match method_call(recv) {
+ Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
+ Some((name2 @ ("into_iter" | "iter" | "iter_mut"), [recv2], _)) => {
+ iter_count::check(cx, expr, recv2, name2);
},
Some(("map", [_, arg], _)) => suspicious_map::check(cx, expr, recv, arg),
_ => {},
},
- ("expect", [_]) => match method_call!(recv) {
+ ("expect", [_]) => match method_call(recv) {
Some(("ok", [recv], _)) => ok_expect::check(cx, expr, recv),
_ => expect_used::check(cx, expr, recv),
},
- ("extend", [arg]) => string_extend_chars::check(cx, expr, recv, arg),
+ ("extend", [arg]) => {
+ string_extend_chars::check(cx, expr, recv, arg);
+ extend_with_drain::check(cx, expr, recv, arg);
+ },
("filter_map", [arg]) => {
unnecessary_filter_map::check(cx, expr, arg);
filter_map_identity::check(cx, expr, arg, span);
},
- ("flat_map", [flm_arg]) => match method_call!(recv) {
- Some(("filter", [_, _], _)) => filter_flat_map::check(cx, expr),
- Some(("filter_map", [_, _], _)) => filter_map_flat_map::check(cx, expr),
- _ => flat_map_identity::check(cx, expr, flm_arg, span),
+ ("flat_map", [arg]) => {
+ flat_map_identity::check(cx, expr, arg, span);
+ flat_map_option::check(cx, expr, arg, span);
},
- ("flatten", []) => {
- if let Some(("map", [recv, map_arg], _)) = method_call!(recv) {
- map_flatten::check(cx, expr, recv, map_arg);
- }
+ (name @ "flatten", args @ []) => match method_call(recv) {
+ Some(("map", [recv, map_arg], _)) => map_flatten::check(cx, expr, recv, map_arg),
+ Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
+ _ => {},
},
("fold", [init, acc]) => unnecessary_fold::check(cx, expr, init, acc, span),
("for_each", [_]) => {
- if let Some(("inspect", [_, _], span2)) = method_call!(recv) {
+ if let Some(("inspect", [_, _], span2)) = method_call(recv) {
inspect_for_each::check(cx, expr, span2);
}
},
("is_file", []) => filetype_is_file::check(cx, expr, recv),
("is_none", []) => check_is_some_is_none(cx, expr, recv, false),
("is_some", []) => check_is_some_is_none(cx, expr, recv, true),
+ ("last", args @ []) | ("skip", args @ [_]) => {
+ if let Some((name2, [recv2, args2 @ ..], _span2)) = method_call(recv) {
+ if let ("cloned", []) = (name2, args2) {
+ iter_overeager_cloned::check(cx, expr, recv2, name, args);
+ }
+ }
+ },
("map", [m_arg]) => {
- if let Some((name, [recv2, args @ ..], span2)) = method_call!(recv) {
+ if let Some((name, [recv2, args @ ..], span2)) = method_call(recv) {
match (name, args) {
("as_mut", []) => option_as_ref_deref::check(cx, expr, recv2, m_arg, true, msrv),
("as_ref", []) => option_as_ref_deref::check(cx, expr, recv2, m_arg, false, msrv),
("filter", [f_arg]) => {
- filter_map::check(cx, expr, recv2, f_arg, span2, recv, m_arg, span, false)
+ filter_map::check(cx, expr, recv2, f_arg, span2, recv, m_arg, span, false);
},
- ("filter_map", [_]) => filter_map_map::check(cx, expr),
("find", [f_arg]) => filter_map::check(cx, expr, recv2, f_arg, span2, recv, m_arg, span, true),
_ => {},
}
}
+ map_identity::check(cx, expr, recv, m_arg, span);
},
("map_or", [def, map]) => option_map_or_none::check(cx, expr, recv, def, map),
- ("next", []) => {
- if let Some((name, [recv, args @ ..], _)) = method_call!(recv) {
- match (name, args) {
- ("filter", [arg]) => filter_next::check(cx, expr, recv, arg),
- ("filter_map", [arg]) => filter_map_next::check(cx, expr, recv, arg, msrv),
- ("iter", []) => iter_next_slice::check(cx, expr, recv),
- ("skip", [arg]) => iter_skip_next::check(cx, expr, recv, arg),
+ (name @ "next", args @ []) => {
+ if let Some((name2, [recv2, args2 @ ..], _)) = method_call(recv) {
+ match (name2, args2) {
+ ("cloned", []) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
+ ("filter", [arg]) => filter_next::check(cx, expr, recv2, arg),
+ ("filter_map", [arg]) => filter_map_next::check(cx, expr, recv2, arg, msrv),
+ ("iter", []) => iter_next_slice::check(cx, expr, recv2),
+ ("skip", [arg]) => iter_skip_next::check(cx, expr, recv2, arg),
("skip_while", [_]) => skip_while_next::check(cx, expr),
_ => {},
}
}
},
- ("nth", [n_arg]) => match method_call!(recv) {
+ ("nth", args @ [n_arg]) => match method_call(recv) {
Some(("bytes", [recv2], _)) => bytes_nth::check(cx, expr, recv2, n_arg),
+ Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
Some(("iter", [recv2], _)) => iter_nth::check(cx, expr, recv2, recv, n_arg, false),
Some(("iter_mut", [recv2], _)) => iter_nth::check(cx, expr, recv2, recv, n_arg, true),
_ => iter_nth_zero::check(cx, expr, recv, n_arg),
unnecessary_lazy_eval::check(cx, expr, recv, arg, "or");
}
},
+ ("splitn" | "rsplitn", [count_arg, pat_arg]) => {
+ if let Some((Constant::Int(count), _)) = constant(cx, cx.typeck_results(), count_arg) {
+ suspicious_splitn::check(cx, name, expr, recv, count);
+ if count == 2 && meets_msrv(msrv, &msrvs::STR_SPLIT_ONCE) {
+ str_splitn::check_manual_split_once(cx, name, expr, recv, pat_arg);
+ }
+ if count >= 2 {
+ str_splitn::check_needless_splitn(cx, name, expr, recv, pat_arg, count);
+ }
+ }
+ },
+ ("splitn_mut" | "rsplitn_mut", [count_arg, _]) => {
+ if let Some((Constant::Int(count), _)) = constant(cx, cx.typeck_results(), count_arg) {
+ suspicious_splitn::check(cx, name, expr, recv, count);
+ }
+ },
("step_by", [arg]) => iterator_step_by_zero::check(cx, expr, arg),
- ("to_os_string", []) => implicit_clone::check(cx, expr, sym::OsStr),
- ("to_owned", []) => implicit_clone::check(cx, expr, sym::ToOwned),
- ("to_path_buf", []) => implicit_clone::check(cx, expr, sym::Path),
- ("to_vec", []) => implicit_clone::check(cx, expr, sym::slice),
- ("unwrap", []) => match method_call!(recv) {
- Some(("get", [recv, get_arg], _)) => get_unwrap::check(cx, expr, recv, get_arg, false),
- Some(("get_mut", [recv, get_arg], _)) => get_unwrap::check(cx, expr, recv, get_arg, true),
- _ => unwrap_used::check(cx, expr, recv),
+ ("take", args @ [_arg]) => {
+ if let Some((name2, [recv2, args2 @ ..], _span2)) = method_call(recv) {
+ if let ("cloned", []) = (name2, args2) {
+ iter_overeager_cloned::check(cx, expr, recv2, name, args);
+ }
+ }
+ },
+ ("to_os_string" | "to_owned" | "to_path_buf" | "to_vec", []) => {
+ implicit_clone::check(cx, name, expr, recv);
},
- ("unwrap_or", [u_arg]) => match method_call!(recv) {
+ ("unwrap", []) => {
+ match method_call(recv) {
+ Some(("get", [recv, get_arg], _)) => {
+ get_unwrap::check(cx, expr, recv, get_arg, false);
+ },
+ Some(("get_mut", [recv, get_arg], _)) => {
+ get_unwrap::check(cx, expr, recv, get_arg, true);
+ },
+ _ => {},
+ }
+ unwrap_used::check(cx, expr, recv);
+ },
+ ("unwrap_or", [u_arg]) => match method_call(recv) {
Some((arith @ ("checked_add" | "checked_sub" | "checked_mul"), [lhs, rhs], _)) => {
manual_saturating_arithmetic::check(cx, expr, lhs, rhs, u_arg, &arith["checked_".len()..]);
},
Some(("map", [m_recv, m_arg], span)) => {
- option_map_unwrap_or::check(cx, expr, m_recv, m_arg, recv, u_arg, span)
+ option_map_unwrap_or::check(cx, expr, m_recv, m_arg, recv, u_arg, span);
},
_ => {},
},
- ("unwrap_or_else", [u_arg]) => match method_call!(recv) {
+ ("unwrap_or_else", [u_arg]) => match method_call(recv) {
Some(("map", [recv, map_arg], _)) if map_unwrap_or::check(cx, expr, recv, map_arg, u_arg, msrv) => {},
- _ => unnecessary_lazy_eval::check(cx, expr, recv, u_arg, "unwrap_or"),
+ _ => {
+ unwrap_or_else_default::check(cx, expr, recv, u_arg);
+ unnecessary_lazy_eval::check(cx, expr, recv, u_arg, "unwrap_or");
+ },
},
_ => {},
}
}
fn check_is_some_is_none(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, is_some: bool) {
- if let Some((name @ ("find" | "position" | "rposition"), [f_recv, arg], span)) = method_call!(recv) {
- search_is_some::check(cx, expr, name, is_some, f_recv, arg, recv, span)
+ if let Some((name @ ("find" | "position" | "rposition"), [f_recv, arg], span)) = method_call(recv) {
+ search_is_some::check(cx, expr, name, is_some, f_recv, arg, recv, span);
}
}
ShouldImplTraitCase::new("std::ops::Sub", "sub", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
];
-#[rustfmt::skip]
-const PATTERN_METHODS: [(&str, usize); 17] = [
- ("contains", 1),
- ("starts_with", 1),
- ("ends_with", 1),
- ("find", 1),
- ("rfind", 1),
- ("split", 1),
- ("rsplit", 1),
- ("split_terminator", 1),
- ("rsplit_terminator", 1),
- ("splitn", 2),
- ("rsplitn", 2),
- ("matches", 1),
- ("rmatches", 1),
- ("match_indices", 1),
- ("rmatch_indices", 1),
- ("trim_start_matches", 1),
- ("trim_end_matches", 1),
-];
-
#[derive(Clone, Copy, PartialEq, Debug)]
enum SelfKind {
Value,
implements_trait(cx, ty, trait_def_id, &[parent_ty.into()])
}
+ fn matches_none<'a>(cx: &LateContext<'a>, parent_ty: Ty<'a>, ty: Ty<'a>) -> bool {
+ !matches_value(cx, parent_ty, ty)
+ && !matches_ref(cx, hir::Mutability::Not, parent_ty, ty)
+ && !matches_ref(cx, hir::Mutability::Mut, parent_ty, ty)
+ }
+
match self {
Self::Value => matches_value(cx, parent_ty, ty),
Self::Ref => matches_ref(cx, hir::Mutability::Not, parent_ty, ty) || ty == parent_ty && is_copy(cx, ty),
Self::RefMut => matches_ref(cx, hir::Mutability::Mut, parent_ty, ty),
- Self::No => ty != parent_ty,
+ Self::No => matches_none(cx, parent_ty, ty),
}
}
projects / rust.git / blobdiff