Add CLONE_ON_REF_PTR lint

Closes issue #1645
This commit is contained in:
Aaron Hill 2017-09-09 21:51:54 -04:00
parent 9c9a4953c3
commit d318ced660
No known key found for this signature in database
GPG Key ID: B4087E510E98B164
5 changed files with 349 additions and 247 deletions

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@ -171,7 +171,7 @@ pub fn lit_to_constant<'a, 'tcx>(lit: &LitKind, tcx: TyCtxt<'a, 'tcx, 'tcx>, mut
match *lit {
LitKind::Str(ref is, style) => Constant::Str(is.to_string(), style),
LitKind::Byte(b) => Constant::Int(ConstInt::U8(b)),
LitKind::ByteStr(ref s) => Constant::Binary(s.clone()),
LitKind::ByteStr(ref s) => Constant::Binary(Rc::clone(s)),
LitKind::Char(c) => Constant::Char(c),
LitKind::Int(n, hint) => match (&ty.sty, hint) {
(&ty::TyInt(ity), _) | (_, Signed(ity)) => {

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@ -310,6 +310,24 @@ declare_lint! {
"using `clone` on a `Copy` type"
}
/// **What it does:** Checks for usage of `.clone()` on a ref-counted pointer,
/// (Rc, Arc, rc::Weak, or sync::Weak), and suggests calling Clone on
/// the corresponding trait instead.
///
/// **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:**
/// ```rust
/// x.clone()
/// ```
declare_lint! {
pub CLONE_ON_REF_PTR,
Warn,
"using 'clone' on a ref-counted pointer"
}
/// **What it does:** Checks for usage of `.clone()` on an `&&T`.
///
/// **Why is this bad?** Cloning an `&&T` copies the inner `&T`, instead of
@ -539,6 +557,7 @@ impl LintPass for Pass {
OR_FUN_CALL,
CHARS_NEXT_CMP,
CLONE_ON_COPY,
CLONE_ON_REF_PTR,
CLONE_DOUBLE_REF,
NEW_RET_NO_SELF,
SINGLE_CHAR_PATTERN,
@ -615,6 +634,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
let self_ty = cx.tables.expr_ty_adjusted(&args[0]);
if args.len() == 1 && method_call.name == "clone" {
lint_clone_on_copy(cx, expr, &args[0], self_ty);
lint_clone_on_ref_ptr(cx, expr, &args[0]);
}
match self_ty.sty {
@ -853,6 +873,34 @@ fn lint_clone_on_copy(cx: &LateContext, expr: &hir::Expr, arg: &hir::Expr, arg_t
}
}
fn lint_clone_on_ref_ptr(cx: &LateContext, expr: &hir::Expr, arg: &hir::Expr) {
let (obj_ty, _) = walk_ptrs_ty_depth(cx.tables.expr_ty(arg));
let caller_type = if match_type(cx, obj_ty, &paths::RC) {
"Rc"
} else if match_type(cx, obj_ty, &paths::ARC) {
"Arc"
} else if match_type(cx, obj_ty, &paths::WEAK_RC) || match_type(cx, obj_ty, &paths::WEAK_ARC) {
"Weak"
} else {
return;
};
span_lint_and_sugg(
cx,
CLONE_ON_REF_PTR,
expr.span,
"using '.clone()' on a ref-counted pointer",
"try this",
format!("{}::clone(&{})",
caller_type,
snippet(cx, arg.span, "_")
)
);
}
fn lint_string_extend(cx: &LateContext, expr: &hir::Expr, args: &[hir::Expr]) {
let arg = &args[1];
if let Some(arglists) = method_chain_args(arg, &["chars"]) {

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@ -2,6 +2,7 @@
//! about.
pub const ANY_TRAIT: [&'static str; 3] = ["std", "any", "Any"];
pub const ARC: [&'static str; 3] = ["alloc", "arc", "Arc"];
pub const ASMUT_TRAIT: [&'static str; 3] = ["core", "convert", "AsMut"];
pub const ASREF_TRAIT: [&'static str; 3] = ["core", "convert", "AsRef"];
pub const BEGIN_PANIC: [&'static str; 3] = ["std", "panicking", "begin_panic"];
@ -58,6 +59,7 @@ pub const RANGE_TO: [&'static str; 3] = ["core", "ops", "RangeTo"];
pub const RANGE_TO_INCLUSIVE: [&'static str; 3] = ["core", "ops", "RangeToInclusive"];
pub const RANGE_TO_INCLUSIVE_STD: [&'static str; 3] = ["std", "ops", "RangeToInclusive"];
pub const RANGE_TO_STD: [&'static str; 3] = ["std", "ops", "RangeTo"];
pub const RC: [&'static str; 3] = ["alloc", "rc", "Rc"];
pub const REGEX: [&'static str; 3] = ["regex", "re_unicode", "Regex"];
pub const REGEX_BUILDER_NEW: [&'static str; 5] = ["regex", "re_builder", "unicode", "RegexBuilder", "new"];
pub const REGEX_BYTES: [&'static str; 3] = ["regex", "re_bytes", "Regex"];
@ -81,3 +83,5 @@ pub const TRY_INTO_RESULT: [&'static str; 4] = ["std", "ops", "Try", "into_resul
pub const VEC: [&'static str; 3] = ["alloc", "vec", "Vec"];
pub const VEC_DEQUE: [&'static str; 3] = ["alloc", "vec_deque", "VecDeque"];
pub const VEC_FROM_ELEM: [&'static str; 3] = ["alloc", "vec", "from_elem"];
pub const WEAK_ARC: [&'static str; 3] = ["alloc", "arc", "Weak"];
pub const WEAK_RC: [&'static str; 3] = ["alloc", "rc", "Weak"];

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@ -11,6 +11,8 @@ use std::collections::HashSet;
use std::collections::VecDeque;
use std::ops::Mul;
use std::iter::FromIterator;
use std::rc::{self, Rc};
use std::sync::{self, Arc};
struct T;
@ -456,6 +458,28 @@ fn clone_on_copy() {
(&42).clone();
}
fn clone_on_ref_ptr() {
let rc = Rc::new(true);
let arc = Arc::new(true);
let rcweak = Rc::downgrade(&rc);
let arc_weak = Arc::downgrade(&arc);
rc.clone();
Rc::clone(&rc);
arc.clone();
Arc::clone(&arc);
rcweak.clone();
rc::Weak::clone(&rcweak);
arc_weak.clone();
sync::Weak::clone(&arc_weak);
}
fn clone_on_copy_generic<T: Copy>(t: T) {
t.clone();

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@ -1,716 +1,742 @@
error: unnecessary structure name repetition
--> $DIR/methods.rs:18:25
--> $DIR/methods.rs:20:25
|
18 | fn add(self, other: T) -> T { self }
20 | fn add(self, other: T) -> T { self }
| ^ help: use the applicable keyword: `Self`
|
= note: `-D use-self` implied by `-D warnings`
error: unnecessary structure name repetition
--> $DIR/methods.rs:18:31
--> $DIR/methods.rs:20:31
|
18 | fn add(self, other: T) -> T { self }
20 | fn add(self, other: T) -> T { self }
| ^ help: use the applicable keyword: `Self`
error: unnecessary structure name repetition
--> $DIR/methods.rs:21:26
--> $DIR/methods.rs:23:26
|
21 | fn sub(&self, other: T) -> &T { self } // no error, self is a ref
23 | fn sub(&self, other: T) -> &T { self } // no error, self is a ref
| ^ help: use the applicable keyword: `Self`
error: unnecessary structure name repetition
--> $DIR/methods.rs:21:33
--> $DIR/methods.rs:23:33
|
21 | fn sub(&self, other: T) -> &T { self } // no error, self is a ref
23 | fn sub(&self, other: T) -> &T { self } // no error, self is a ref
| ^ help: use the applicable keyword: `Self`
error: unnecessary structure name repetition
--> $DIR/methods.rs:22:21
--> $DIR/methods.rs:24:21
|
22 | fn div(self) -> T { self } // no error, different #arguments
24 | fn div(self) -> T { self } // no error, different #arguments
| ^ help: use the applicable keyword: `Self`
error: unnecessary structure name repetition
--> $DIR/methods.rs:23:25
--> $DIR/methods.rs:25:25
|
23 | fn rem(self, other: T) { } // no error, wrong return type
25 | fn rem(self, other: T) { } // no error, wrong return type
| ^ help: use the applicable keyword: `Self`
error: defining a method called `add` on this type; consider implementing the `std::ops::Add` trait or choosing a less ambiguous name
--> $DIR/methods.rs:18:5
--> $DIR/methods.rs:20:5
|
18 | fn add(self, other: T) -> T { self }
20 | fn add(self, other: T) -> T { self }
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D should-implement-trait` implied by `-D warnings`
error: defining a method called `drop` on this type; consider implementing the `std::ops::Drop` trait or choosing a less ambiguous name
--> $DIR/methods.rs:19:5
--> $DIR/methods.rs:21:5
|
19 | fn drop(&mut self) { }
21 | fn drop(&mut self) { }
| ^^^^^^^^^^^^^^^^^^^^^^
error: methods called `into_*` usually take self by value; consider choosing a less ambiguous name
--> $DIR/methods.rs:26:17
--> $DIR/methods.rs:28:17
|
26 | fn into_u16(&self) -> u16 { 0 }
28 | fn into_u16(&self) -> u16 { 0 }
| ^^^^^
|
= note: `-D wrong-self-convention` implied by `-D warnings`
error: methods called `to_*` usually take self by reference; consider choosing a less ambiguous name
--> $DIR/methods.rs:28:21
--> $DIR/methods.rs:30:21
|
28 | fn to_something(self) -> u32 { 0 }
30 | fn to_something(self) -> u32 { 0 }
| ^^^^
error: methods called `new` usually take no self; consider choosing a less ambiguous name
--> $DIR/methods.rs:30:12
--> $DIR/methods.rs:32:12
|
30 | fn new(self) {}
32 | fn new(self) {}
| ^^^^
error: methods called `new` usually return `Self`
--> $DIR/methods.rs:30:5
--> $DIR/methods.rs:32:5
|
30 | fn new(self) {}
32 | fn new(self) {}
| ^^^^^^^^^^^^^^^
|
= note: `-D new-ret-no-self` implied by `-D warnings`
error: unnecessary structure name repetition
--> $DIR/methods.rs:74:24
--> $DIR/methods.rs:76:24
|
74 | fn new() -> Option<V<T>> { None }
76 | fn new() -> Option<V<T>> { None }
| ^^^^ help: use the applicable keyword: `Self`
error: unnecessary structure name repetition
--> $DIR/methods.rs:78:19
--> $DIR/methods.rs:80:19
|
78 | type Output = T;
80 | type Output = T;
| ^ help: use the applicable keyword: `Self`
error: unnecessary structure name repetition
--> $DIR/methods.rs:79:25
--> $DIR/methods.rs:81:25
|
79 | fn mul(self, other: T) -> T { self } // no error, obviously
81 | fn mul(self, other: T) -> T { self } // no error, obviously
| ^ help: use the applicable keyword: `Self`
error: unnecessary structure name repetition
--> $DIR/methods.rs:79:31
--> $DIR/methods.rs:81:31
|
79 | fn mul(self, other: T) -> T { self } // no error, obviously
81 | fn mul(self, other: T) -> T { self } // no error, obviously
| ^ help: use the applicable keyword: `Self`
error: called `map(f).unwrap_or(a)` on an Option value. This can be done more directly by calling `map_or(a, f)` instead
--> $DIR/methods.rs:97:13
|
97 | let _ = opt.map(|x| x + 1)
| _____________^
98 | |
99 | | .unwrap_or(0); // should lint even though this call is on a separate line
| |____________________________^
|
= note: `-D option-map-unwrap-or` implied by `-D warnings`
= note: replace `map(|x| x + 1).unwrap_or(0)` with `map_or(0, |x| x + 1)`
--> $DIR/methods.rs:99:13
|
99 | let _ = opt.map(|x| x + 1)
| _____________^
100 | |
101 | | .unwrap_or(0); // should lint even though this call is on a separate line
| |____________________________^
|
= note: `-D option-map-unwrap-or` implied by `-D warnings`
= note: replace `map(|x| x + 1).unwrap_or(0)` with `map_or(0, |x| x + 1)`
error: called `map(f).unwrap_or(a)` on an Option value. This can be done more directly by calling `map_or(a, f)` instead
--> $DIR/methods.rs:101:13
--> $DIR/methods.rs:103:13
|
101 | let _ = opt.map(|x| {
103 | let _ = opt.map(|x| {
| _____________^
102 | | x + 1
103 | | }
104 | | ).unwrap_or(0);
104 | | x + 1
105 | | }
106 | | ).unwrap_or(0);
| |____________________________^
error: called `map(f).unwrap_or(a)` on an Option value. This can be done more directly by calling `map_or(a, f)` instead
--> $DIR/methods.rs:105:13
--> $DIR/methods.rs:107:13
|
105 | let _ = opt.map(|x| x + 1)
107 | let _ = opt.map(|x| x + 1)
| _____________^
106 | | .unwrap_or({
107 | | 0
108 | | });
108 | | .unwrap_or({
109 | | 0
110 | | });
| |__________________^
error: called `map(f).unwrap_or_else(g)` on an Option value. This can be done more directly by calling `map_or_else(g, f)` instead
--> $DIR/methods.rs:114:13
--> $DIR/methods.rs:116:13
|
114 | let _ = opt.map(|x| x + 1)
116 | let _ = opt.map(|x| x + 1)
| _____________^
115 | |
116 | | .unwrap_or_else(|| 0); // should lint even though this call is on a separate line
117 | |
118 | | .unwrap_or_else(|| 0); // should lint even though this call is on a separate line
| |____________________________________^
|
= note: `-D option-map-unwrap-or-else` implied by `-D warnings`
= note: replace `map(|x| x + 1).unwrap_or_else(|| 0)` with `map_or_else(|| 0, |x| x + 1)`
error: called `map(f).unwrap_or_else(g)` on an Option value. This can be done more directly by calling `map_or_else(g, f)` instead
--> $DIR/methods.rs:118:13
--> $DIR/methods.rs:120:13
|
118 | let _ = opt.map(|x| {
120 | let _ = opt.map(|x| {
| _____________^
119 | | x + 1
120 | | }
121 | | ).unwrap_or_else(|| 0);
121 | | x + 1
122 | | }
123 | | ).unwrap_or_else(|| 0);
| |____________________________________^
error: called `map(f).unwrap_or_else(g)` on an Option value. This can be done more directly by calling `map_or_else(g, f)` instead
--> $DIR/methods.rs:122:13
--> $DIR/methods.rs:124:13
|
122 | let _ = opt.map(|x| x + 1)
124 | let _ = opt.map(|x| x + 1)
| _____________^
123 | | .unwrap_or_else(||
124 | | 0
125 | | );
125 | | .unwrap_or_else(||
126 | | 0
127 | | );
| |_________________^
error: unnecessary structure name repetition
--> $DIR/methods.rs:151:24
--> $DIR/methods.rs:153:24
|
151 | fn filter(self) -> IteratorFalsePositives {
153 | fn filter(self) -> IteratorFalsePositives {
| ^^^^^^^^^^^^^^^^^^^^^^ help: use the applicable keyword: `Self`
error: unnecessary structure name repetition
--> $DIR/methods.rs:155:22
--> $DIR/methods.rs:157:22
|
155 | fn next(self) -> IteratorFalsePositives {
157 | fn next(self) -> IteratorFalsePositives {
| ^^^^^^^^^^^^^^^^^^^^^^ help: use the applicable keyword: `Self`
error: unnecessary structure name repetition
--> $DIR/methods.rs:175:32
--> $DIR/methods.rs:177:32
|
175 | fn skip(self, _: usize) -> IteratorFalsePositives {
177 | fn skip(self, _: usize) -> IteratorFalsePositives {
| ^^^^^^^^^^^^^^^^^^^^^^ help: use the applicable keyword: `Self`
error: called `filter(p).next()` on an `Iterator`. This is more succinctly expressed by calling `.find(p)` instead.
--> $DIR/methods.rs:194:13
--> $DIR/methods.rs:196:13
|
194 | let _ = v.iter().filter(|&x| *x < 0).next();
196 | let _ = v.iter().filter(|&x| *x < 0).next();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D filter-next` implied by `-D warnings`
= note: replace `filter(|&x| *x < 0).next()` with `find(|&x| *x < 0)`
error: called `filter(p).next()` on an `Iterator`. This is more succinctly expressed by calling `.find(p)` instead.
--> $DIR/methods.rs:197:13
--> $DIR/methods.rs:199:13
|
197 | let _ = v.iter().filter(|&x| {
199 | let _ = v.iter().filter(|&x| {
| _____________^
198 | | *x < 0
199 | | }
200 | | ).next();
200 | | *x < 0
201 | | }
202 | | ).next();
| |___________________________^
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:212:13
--> $DIR/methods.rs:214:13
|
212 | let _ = v.iter().find(|&x| *x < 0).is_some();
214 | let _ = v.iter().find(|&x| *x < 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D search-is-some` implied by `-D warnings`
= note: replace `find(|&x| *x < 0).is_some()` with `any(|&x| *x < 0)`
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:215:13
--> $DIR/methods.rs:217:13
|
215 | let _ = v.iter().find(|&x| {
217 | let _ = v.iter().find(|&x| {
| _____________^
216 | | *x < 0
217 | | }
218 | | ).is_some();
218 | | *x < 0
219 | | }
220 | | ).is_some();
| |______________________________^
error: called `is_some()` after searching an `Iterator` with position. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:221:13
--> $DIR/methods.rs:223:13
|
221 | let _ = v.iter().position(|&x| x < 0).is_some();
223 | let _ = v.iter().position(|&x| x < 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: replace `position(|&x| x < 0).is_some()` with `any(|&x| x < 0)`
error: called `is_some()` after searching an `Iterator` with position. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:224:13
--> $DIR/methods.rs:226:13
|
224 | let _ = v.iter().position(|&x| {
226 | let _ = v.iter().position(|&x| {
| _____________^
225 | | x < 0
226 | | }
227 | | ).is_some();
227 | | x < 0
228 | | }
229 | | ).is_some();
| |______________________________^
error: called `is_some()` after searching an `Iterator` with rposition. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:230:13
--> $DIR/methods.rs:232:13
|
230 | let _ = v.iter().rposition(|&x| x < 0).is_some();
232 | let _ = v.iter().rposition(|&x| x < 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: replace `rposition(|&x| x < 0).is_some()` with `any(|&x| x < 0)`
error: called `is_some()` after searching an `Iterator` with rposition. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:233:13
--> $DIR/methods.rs:235:13
|
233 | let _ = v.iter().rposition(|&x| {
235 | let _ = v.iter().rposition(|&x| {
| _____________^
234 | | x < 0
235 | | }
236 | | ).is_some();
236 | | x < 0
237 | | }
238 | | ).is_some();
| |______________________________^
error: unnecessary structure name repetition
--> $DIR/methods.rs:250:21
--> $DIR/methods.rs:252:21
|
250 | fn new() -> Foo { Foo }
252 | fn new() -> Foo { Foo }
| ^^^ help: use the applicable keyword: `Self`
error: use of `unwrap_or` followed by a function call
--> $DIR/methods.rs:268:5
--> $DIR/methods.rs:270:5
|
268 | with_constructor.unwrap_or(make());
270 | with_constructor.unwrap_or(make());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `with_constructor.unwrap_or_else(make)`
|
= note: `-D or-fun-call` implied by `-D warnings`
error: use of `unwrap_or` followed by a call to `new`
--> $DIR/methods.rs:271:5
--> $DIR/methods.rs:273:5
|
271 | with_new.unwrap_or(Vec::new());
273 | with_new.unwrap_or(Vec::new());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `with_new.unwrap_or_default()`
error: use of `unwrap_or` followed by a function call
--> $DIR/methods.rs:274:5
--> $DIR/methods.rs:276:5
|
274 | with_const_args.unwrap_or(Vec::with_capacity(12));
276 | with_const_args.unwrap_or(Vec::with_capacity(12));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `with_const_args.unwrap_or_else(|| Vec::with_capacity(12))`
error: use of `unwrap_or` followed by a function call
--> $DIR/methods.rs:277:5
--> $DIR/methods.rs:279:5
|
277 | with_err.unwrap_or(make());
279 | with_err.unwrap_or(make());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `with_err.unwrap_or_else(|_| make())`
error: use of `unwrap_or` followed by a function call
--> $DIR/methods.rs:280:5
--> $DIR/methods.rs:282:5
|
280 | with_err_args.unwrap_or(Vec::with_capacity(12));
282 | with_err_args.unwrap_or(Vec::with_capacity(12));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `with_err_args.unwrap_or_else(|_| Vec::with_capacity(12))`
error: use of `unwrap_or` followed by a call to `default`
--> $DIR/methods.rs:283:5
--> $DIR/methods.rs:285:5
|
283 | with_default_trait.unwrap_or(Default::default());
285 | with_default_trait.unwrap_or(Default::default());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `with_default_trait.unwrap_or_default()`
error: use of `unwrap_or` followed by a call to `default`
--> $DIR/methods.rs:286:5
--> $DIR/methods.rs:288:5
|
286 | with_default_type.unwrap_or(u64::default());
288 | with_default_type.unwrap_or(u64::default());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `with_default_type.unwrap_or_default()`
error: use of `unwrap_or` followed by a function call
--> $DIR/methods.rs:289:5
--> $DIR/methods.rs:291:5
|
289 | with_vec.unwrap_or(vec![]);
291 | with_vec.unwrap_or(vec![]);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `with_vec.unwrap_or_else(|| < [ _ ] > :: into_vec ( box [ $ ( $ x ) , * ] ))`
error: use of `unwrap_or` followed by a function call
--> $DIR/methods.rs:294:5
--> $DIR/methods.rs:296:5
|
294 | without_default.unwrap_or(Foo::new());
296 | without_default.unwrap_or(Foo::new());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `without_default.unwrap_or_else(Foo::new)`
error: use of `or_insert` followed by a function call
--> $DIR/methods.rs:297:5
--> $DIR/methods.rs:299:5
|
297 | map.entry(42).or_insert(String::new());
299 | map.entry(42).or_insert(String::new());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `map.entry(42).or_insert_with(String::new)`
error: use of `or_insert` followed by a function call
--> $DIR/methods.rs:300:5
--> $DIR/methods.rs:302:5
|
300 | btree.entry(42).or_insert(String::new());
302 | btree.entry(42).or_insert(String::new());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `btree.entry(42).or_insert_with(String::new)`
error: use of `unwrap_or` followed by a function call
--> $DIR/methods.rs:303:13
--> $DIR/methods.rs:305:13
|
303 | let _ = stringy.unwrap_or("".to_owned());
305 | let _ = stringy.unwrap_or("".to_owned());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `stringy.unwrap_or_else(|| "".to_owned())`
error: called `.iter().nth()` on a Vec. Calling `.get()` is both faster and more readable
--> $DIR/methods.rs:314:23
--> $DIR/methods.rs:316:23
|
314 | let bad_vec = some_vec.iter().nth(3);
316 | let bad_vec = some_vec.iter().nth(3);
| ^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D iter-nth` implied by `-D warnings`
error: called `.iter().nth()` on a slice. Calling `.get()` is both faster and more readable
--> $DIR/methods.rs:315:26
--> $DIR/methods.rs:317:26
|
315 | let bad_slice = &some_vec[..].iter().nth(3);
317 | let bad_slice = &some_vec[..].iter().nth(3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
error: called `.iter().nth()` on a slice. Calling `.get()` is both faster and more readable
--> $DIR/methods.rs:316:31
--> $DIR/methods.rs:318:31
|
316 | let bad_boxed_slice = boxed_slice.iter().nth(3);
318 | let bad_boxed_slice = boxed_slice.iter().nth(3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^
error: called `.iter().nth()` on a VecDeque. Calling `.get()` is both faster and more readable
--> $DIR/methods.rs:317:29
--> $DIR/methods.rs:319:29
|
317 | let bad_vec_deque = some_vec_deque.iter().nth(3);
319 | let bad_vec_deque = some_vec_deque.iter().nth(3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: called `.iter_mut().nth()` on a Vec. Calling `.get_mut()` is both faster and more readable
--> $DIR/methods.rs:322:23
--> $DIR/methods.rs:324:23
|
322 | let bad_vec = some_vec.iter_mut().nth(3);
324 | let bad_vec = some_vec.iter_mut().nth(3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
error: called `.iter_mut().nth()` on a slice. Calling `.get_mut()` is both faster and more readable
--> $DIR/methods.rs:325:26
--> $DIR/methods.rs:327:26
|
325 | let bad_slice = &some_vec[..].iter_mut().nth(3);
327 | let bad_slice = &some_vec[..].iter_mut().nth(3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: called `.iter_mut().nth()` on a VecDeque. Calling `.get_mut()` is both faster and more readable
--> $DIR/methods.rs:328:29
--> $DIR/methods.rs:330:29
|
328 | let bad_vec_deque = some_vec_deque.iter_mut().nth(3);
330 | let bad_vec_deque = some_vec_deque.iter_mut().nth(3);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: called `skip(x).next()` on an iterator. This is more succinctly expressed by calling `nth(x)`
--> $DIR/methods.rs:340:13
--> $DIR/methods.rs:342:13
|
340 | let _ = some_vec.iter().skip(42).next();
342 | let _ = some_vec.iter().skip(42).next();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D iter-skip-next` implied by `-D warnings`
error: called `skip(x).next()` on an iterator. This is more succinctly expressed by calling `nth(x)`
--> $DIR/methods.rs:341:13
--> $DIR/methods.rs:343:13
|
341 | let _ = some_vec.iter().cycle().skip(42).next();
343 | let _ = some_vec.iter().cycle().skip(42).next();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: called `skip(x).next()` on an iterator. This is more succinctly expressed by calling `nth(x)`
--> $DIR/methods.rs:342:13
--> $DIR/methods.rs:344:13
|
342 | let _ = (1..10).skip(10).next();
344 | let _ = (1..10).skip(10).next();
| ^^^^^^^^^^^^^^^^^^^^^^^
error: called `skip(x).next()` on an iterator. This is more succinctly expressed by calling `nth(x)`
--> $DIR/methods.rs:343:14
--> $DIR/methods.rs:345:14
|
343 | let _ = &some_vec[..].iter().skip(3).next();
345 | let _ = &some_vec[..].iter().skip(3).next();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: called `.get().unwrap()` on a slice. Using `[]` is more clear and more concise
--> $DIR/methods.rs:369:17
--> $DIR/methods.rs:371:17
|
369 | let _ = boxed_slice.get(1).unwrap();
371 | let _ = boxed_slice.get(1).unwrap();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&boxed_slice[1]`
|
= note: `-D get-unwrap` implied by `-D warnings`
error: called `.get().unwrap()` on a slice. Using `[]` is more clear and more concise
--> $DIR/methods.rs:370:17
--> $DIR/methods.rs:372:17
|
370 | let _ = some_slice.get(0).unwrap();
372 | let _ = some_slice.get(0).unwrap();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&some_slice[0]`
error: called `.get().unwrap()` on a Vec. Using `[]` is more clear and more concise
--> $DIR/methods.rs:371:17
--> $DIR/methods.rs:373:17
|
371 | let _ = some_vec.get(0).unwrap();
373 | let _ = some_vec.get(0).unwrap();
| ^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&some_vec[0]`
error: called `.get().unwrap()` on a VecDeque. Using `[]` is more clear and more concise
--> $DIR/methods.rs:372:17
--> $DIR/methods.rs:374:17
|
372 | let _ = some_vecdeque.get(0).unwrap();
374 | let _ = some_vecdeque.get(0).unwrap();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&some_vecdeque[0]`
error: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
--> $DIR/methods.rs:373:17
--> $DIR/methods.rs:375:17
|
373 | let _ = some_hashmap.get(&1).unwrap();
375 | let _ = some_hashmap.get(&1).unwrap();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&some_hashmap[&1]`
error: called `.get().unwrap()` on a BTreeMap. Using `[]` is more clear and more concise
--> $DIR/methods.rs:374:17
--> $DIR/methods.rs:376:17
|
374 | let _ = some_btreemap.get(&1).unwrap();
376 | let _ = some_btreemap.get(&1).unwrap();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&some_btreemap[&1]`
error: called `.get_mut().unwrap()` on a slice. Using `[]` is more clear and more concise
--> $DIR/methods.rs:379:10
--> $DIR/methods.rs:381:10
|
379 | *boxed_slice.get_mut(0).unwrap() = 1;
381 | *boxed_slice.get_mut(0).unwrap() = 1;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&mut boxed_slice[0]`
error: called `.get_mut().unwrap()` on a slice. Using `[]` is more clear and more concise
--> $DIR/methods.rs:380:10
--> $DIR/methods.rs:382:10
|
380 | *some_slice.get_mut(0).unwrap() = 1;
382 | *some_slice.get_mut(0).unwrap() = 1;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&mut some_slice[0]`
error: called `.get_mut().unwrap()` on a Vec. Using `[]` is more clear and more concise
--> $DIR/methods.rs:381:10
--> $DIR/methods.rs:383:10
|
381 | *some_vec.get_mut(0).unwrap() = 1;
383 | *some_vec.get_mut(0).unwrap() = 1;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&mut some_vec[0]`
error: called `.get_mut().unwrap()` on a VecDeque. Using `[]` is more clear and more concise
--> $DIR/methods.rs:382:10
--> $DIR/methods.rs:384:10
|
382 | *some_vecdeque.get_mut(0).unwrap() = 1;
384 | *some_vecdeque.get_mut(0).unwrap() = 1;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&mut some_vecdeque[0]`
error: used unwrap() on an Option value. If you don't want to handle the None case gracefully, consider using expect() to provide a better panic message
--> $DIR/methods.rs:396:13
--> $DIR/methods.rs:398:13
|
396 | let _ = opt.unwrap();
398 | let _ = opt.unwrap();
| ^^^^^^^^^^^^
|
= note: `-D option-unwrap-used` implied by `-D warnings`
error: used unwrap() on a Result value. If you don't want to handle the Err case gracefully, consider using expect() to provide a better panic message
--> $DIR/methods.rs:399:13
--> $DIR/methods.rs:401:13
|
399 | let _ = res.unwrap();
401 | let _ = res.unwrap();
| ^^^^^^^^^^^^
|
= note: `-D result-unwrap-used` implied by `-D warnings`
error: called `ok().expect()` on a Result value. You can call `expect` directly on the `Result`
--> $DIR/methods.rs:401:5
--> $DIR/methods.rs:403:5
|
401 | res.ok().expect("disaster!");
403 | res.ok().expect("disaster!");
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D ok-expect` implied by `-D warnings`
error: called `ok().expect()` on a Result value. You can call `expect` directly on the `Result`
--> $DIR/methods.rs:407:5
|
407 | res3.ok().expect("whoof");
| ^^^^^^^^^^^^^^^^^^^^^^^^^
error: called `ok().expect()` on a Result value. You can call `expect` directly on the `Result`
--> $DIR/methods.rs:409:5
|
409 | res4.ok().expect("argh");
| ^^^^^^^^^^^^^^^^^^^^^^^^
409 | res3.ok().expect("whoof");
| ^^^^^^^^^^^^^^^^^^^^^^^^^
error: called `ok().expect()` on a Result value. You can call `expect` directly on the `Result`
--> $DIR/methods.rs:411:5
|
411 | res5.ok().expect("oops");
411 | res4.ok().expect("argh");
| ^^^^^^^^^^^^^^^^^^^^^^^^
error: called `ok().expect()` on a Result value. You can call `expect` directly on the `Result`
--> $DIR/methods.rs:413:5
|
413 | res6.ok().expect("meh");
413 | res5.ok().expect("oops");
| ^^^^^^^^^^^^^^^^^^^^^^^^
error: called `ok().expect()` on a Result value. You can call `expect` directly on the `Result`
--> $DIR/methods.rs:415:5
|
415 | res6.ok().expect("meh");
| ^^^^^^^^^^^^^^^^^^^^^^^
error: you should use the `starts_with` method
--> $DIR/methods.rs:425:5
--> $DIR/methods.rs:427:5
|
425 | "".chars().next() == Some(' ');
427 | "".chars().next() == Some(' ');
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: like this: `"".starts_with(' ')`
|
= note: `-D chars-next-cmp` implied by `-D warnings`
error: you should use the `starts_with` method
--> $DIR/methods.rs:426:5
--> $DIR/methods.rs:428:5
|
426 | Some(' ') != "".chars().next();
428 | Some(' ') != "".chars().next();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: like this: `!"".starts_with(' ')`
error: calling `.extend(_.chars())`
--> $DIR/methods.rs:435:5
--> $DIR/methods.rs:437:5
|
435 | s.extend(abc.chars());
437 | s.extend(abc.chars());
| ^^^^^^^^^^^^^^^^^^^^^ help: try this: `s.push_str(abc)`
|
= note: `-D string-extend-chars` implied by `-D warnings`
error: calling `.extend(_.chars())`
--> $DIR/methods.rs:438:5
--> $DIR/methods.rs:440:5
|
438 | s.extend("abc".chars());
440 | s.extend("abc".chars());
| ^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `s.push_str("abc")`
error: calling `.extend(_.chars())`
--> $DIR/methods.rs:441:5
--> $DIR/methods.rs:443:5
|
441 | s.extend(def.chars());
443 | s.extend(def.chars());
| ^^^^^^^^^^^^^^^^^^^^^ help: try this: `s.push_str(&def)`
error: using `clone` on a `Copy` type
--> $DIR/methods.rs:452:5
--> $DIR/methods.rs:454:5
|
452 | 42.clone();
454 | 42.clone();
| ^^^^^^^^^^ help: try removing the `clone` call: `42`
|
= note: `-D clone-on-copy` implied by `-D warnings`
error: using `clone` on a `Copy` type
--> $DIR/methods.rs:456:5
--> $DIR/methods.rs:458:5
|
456 | (&42).clone();
458 | (&42).clone();
| ^^^^^^^^^^^^^ help: try dereferencing it: `*(&42)`
error: using `clone` on a `Copy` type
--> $DIR/methods.rs:460:5
error: using '.clone()' on a ref-counted pointer
--> $DIR/methods.rs:468:5
|
460 | t.clone();
468 | rc.clone();
| ^^^^^^^^^^ help: try this: `Rc::clone(&rc)`
|
= note: `-D clone-on-ref-ptr` implied by `-D warnings`
error: using '.clone()' on a ref-counted pointer
--> $DIR/methods.rs:471:5
|
471 | arc.clone();
| ^^^^^^^^^^^ help: try this: `Arc::clone(&arc)`
error: using '.clone()' on a ref-counted pointer
--> $DIR/methods.rs:474:5
|
474 | rcweak.clone();
| ^^^^^^^^^^^^^^ help: try this: `Weak::clone(&rcweak)`
error: using '.clone()' on a ref-counted pointer
--> $DIR/methods.rs:477:5
|
477 | arc_weak.clone();
| ^^^^^^^^^^^^^^^^ help: try this: `Weak::clone(&arc_weak)`
error: using `clone` on a `Copy` type
--> $DIR/methods.rs:484:5
|
484 | t.clone();
| ^^^^^^^^^ help: try removing the `clone` call: `t`
error: using `clone` on a `Copy` type
--> $DIR/methods.rs:462:5
--> $DIR/methods.rs:486:5
|
462 | Some(t).clone();
486 | Some(t).clone();
| ^^^^^^^^^^^^^^^ help: try removing the `clone` call: `Some(t)`
error: using `clone` on a double-reference; this will copy the reference instead of cloning the inner type
--> $DIR/methods.rs:468:22
--> $DIR/methods.rs:492:22
|
468 | let z: &Vec<_> = y.clone();
492 | let z: &Vec<_> = y.clone();
| ^^^^^^^^^ help: try dereferencing it: `(*y).clone()`
|
= note: `-D clone-double-ref` implied by `-D warnings`
error: single-character string constant used as pattern
--> $DIR/methods.rs:475:13
--> $DIR/methods.rs:499:13
|
475 | x.split("x");
499 | x.split("x");
| --------^^^- help: try using a char instead: `x.split('x')`
|
= note: `-D single-char-pattern` implied by `-D warnings`
error: single-character string constant used as pattern
--> $DIR/methods.rs:492:16
--> $DIR/methods.rs:516:16
|
492 | x.contains("x");
516 | x.contains("x");
| -----------^^^- help: try using a char instead: `x.contains('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:493:19
--> $DIR/methods.rs:517:19
|
493 | x.starts_with("x");
517 | x.starts_with("x");
| --------------^^^- help: try using a char instead: `x.starts_with('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:494:17
--> $DIR/methods.rs:518:17
|
494 | x.ends_with("x");
518 | x.ends_with("x");
| ------------^^^- help: try using a char instead: `x.ends_with('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:495:12
--> $DIR/methods.rs:519:12
|
495 | x.find("x");
519 | x.find("x");
| -------^^^- help: try using a char instead: `x.find('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:496:13
--> $DIR/methods.rs:520:13
|
496 | x.rfind("x");
520 | x.rfind("x");
| --------^^^- help: try using a char instead: `x.rfind('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:497:14
--> $DIR/methods.rs:521:14
|
497 | x.rsplit("x");
521 | x.rsplit("x");
| ---------^^^- help: try using a char instead: `x.rsplit('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:498:24
--> $DIR/methods.rs:522:24
|
498 | x.split_terminator("x");
522 | x.split_terminator("x");
| -------------------^^^- help: try using a char instead: `x.split_terminator('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:499:25
--> $DIR/methods.rs:523:25
|
499 | x.rsplit_terminator("x");
523 | x.rsplit_terminator("x");
| --------------------^^^- help: try using a char instead: `x.rsplit_terminator('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:500:17
--> $DIR/methods.rs:524:17
|
500 | x.splitn(0, "x");
524 | x.splitn(0, "x");
| ------------^^^- help: try using a char instead: `x.splitn(0, 'x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:501:18
--> $DIR/methods.rs:525:18
|
501 | x.rsplitn(0, "x");
525 | x.rsplitn(0, "x");
| -------------^^^- help: try using a char instead: `x.rsplitn(0, 'x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:502:15
--> $DIR/methods.rs:526:15
|
502 | x.matches("x");
526 | x.matches("x");
| ----------^^^- help: try using a char instead: `x.matches('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:503:16
--> $DIR/methods.rs:527:16
|
503 | x.rmatches("x");
527 | x.rmatches("x");
| -----------^^^- help: try using a char instead: `x.rmatches('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:504:21
--> $DIR/methods.rs:528:21
|
504 | x.match_indices("x");
528 | x.match_indices("x");
| ----------------^^^- help: try using a char instead: `x.match_indices('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:505:22
--> $DIR/methods.rs:529:22
|
505 | x.rmatch_indices("x");
529 | x.rmatch_indices("x");
| -----------------^^^- help: try using a char instead: `x.rmatch_indices('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:506:25
--> $DIR/methods.rs:530:25
|
506 | x.trim_left_matches("x");
530 | x.trim_left_matches("x");
| --------------------^^^- help: try using a char instead: `x.trim_left_matches('x')`
error: single-character string constant used as pattern
--> $DIR/methods.rs:507:26
--> $DIR/methods.rs:531:26
|
507 | x.trim_right_matches("x");
531 | x.trim_right_matches("x");
| ---------------------^^^- help: try using a char instead: `x.trim_right_matches('x')`
error: you are getting the inner pointer of a temporary `CString`
--> $DIR/methods.rs:517:5
--> $DIR/methods.rs:541:5
|
517 | CString::new("foo").unwrap().as_ptr();
541 | CString::new("foo").unwrap().as_ptr();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D temporary-cstring-as-ptr` implied by `-D warnings`
= note: that pointer will be invalid outside this expression
help: assign the `CString` to a variable to extend its lifetime
--> $DIR/methods.rs:517:5
--> $DIR/methods.rs:541:5
|
517 | CString::new("foo").unwrap().as_ptr();
541 | CString::new("foo").unwrap().as_ptr();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: called `cloned().collect()` on a slice to create a `Vec`. Calling `to_vec()` is both faster and more readable
--> $DIR/methods.rs:522:27
--> $DIR/methods.rs:546:27
|
522 | let v2 : Vec<isize> = v.iter().cloned().collect();
546 | let v2 : Vec<isize> = v.iter().cloned().collect();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D iter-cloned-collect` implied by `-D warnings`
error: aborting due to 103 previous errors
error: aborting due to 107 previous errors