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Auto merge of #13108 - tesuji:fix_redundant_closure, r=xFrednet

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Fix `redundant_closure` false positive with closures has return type contains  `'static`

Fix #13073 .

Please enable "ignore white-space change" settings in github UI for easy reviewing.

HACK: The third commit contains a hack to check if a type `T: 'static` when `fn() -> U where U: 'static`.
I don't have a clean way to check for it.

changelog: [`redundant_closure`] Fix false positive with closures has return type contains  `'static`
This commit is contained in:
bors 2024-08-01 07:55:37 +00:00
commit 2fc74a3931
4 changed files with 252 additions and 187 deletions
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331
clippy_lints/src/eta_reduction.rs
View file

@ -9,8 +9,7 @@ use rustc_hir::{BindingMode, Expr, ExprKind, FnRetTy, Param, PatKind, QPath, Saf
use rustc_infer::infer::TyCtxtInferExt; use rustc_infer::infer::TyCtxtInferExt;
use rustc_lint::{LateContext, LateLintPass}; use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty::{ use rustc_middle::ty::{
self, Binder, ClosureArgs, ClosureKind, FnSig, GenericArg, GenericArgKind, List, Region, RegionKind, Ty, TyCtxt, self, Binder, ClosureKind, FnSig, GenericArg, GenericArgKind, List, Region, Ty, TypeVisitableExt, TypeckResults,
TypeVisitableExt, TypeckResults,
}; };
use rustc_session::declare_lint_pass; use rustc_session::declare_lint_pass;
use rustc_span::symbol::sym; use rustc_span::symbol::sym;
@ -74,159 +73,184 @@ declare_clippy_lint! {
declare_lint_pass!(EtaReduction => [REDUNDANT_CLOSURE, REDUNDANT_CLOSURE_FOR_METHOD_CALLS]); declare_lint_pass!(EtaReduction => [REDUNDANT_CLOSURE, REDUNDANT_CLOSURE_FOR_METHOD_CALLS]);
impl<'tcx> LateLintPass<'tcx> for EtaReduction { impl<'tcx> LateLintPass<'tcx> for EtaReduction {
#[allow(clippy::too_many_lines)] fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &Expr<'tcx>) {
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { if let ExprKind::MethodCall(_method, receiver, args, _) = expr.kind {
let body = if let ExprKind::Closure(c) = expr.kind for arg in args {
&& c.fn_decl.inputs.iter().all(|ty| matches!(ty.kind, TyKind::Infer)) check_clousure(cx, Some(receiver), arg);
&& matches!(c.fn_decl.output, FnRetTy::DefaultReturn(_))
&& !expr.span.from_expansion()
{
cx.tcx.hir().body(c.body)
} else {
return;
};
if body.value.span.from_expansion() {
if body.params.is_empty() {
if let Some(VecArgs::Vec(&[])) = VecArgs::hir(cx, body.value) {
// replace `|| vec![]` with `Vec::new`
span_lint_and_sugg(
cx,
REDUNDANT_CLOSURE,
expr.span,
"redundant closure",
"replace the closure with `Vec::new`",
"std::vec::Vec::new".into(),
Applicability::MachineApplicable,
);
}
} }
// skip `foo(|| macro!())`
return;
} }
if let ExprKind::Call(func, args) = expr.kind {
let typeck = cx.typeck_results(); check_clousure(cx, None, func);
let closure = if let ty::Closure(_, closure_subs) = typeck.expr_ty(expr).kind() { for arg in args {
closure_subs.as_closure() check_clousure(cx, None, arg);
} else { }
return;
};
if is_adjusted(cx, body.value) {
return;
} }
}
}
match body.value.kind { #[allow(clippy::too_many_lines)]
ExprKind::Call(callee, args) fn check_clousure<'tcx>(cx: &LateContext<'tcx>, outer_receiver: Option<&Expr<'tcx>>, expr: &Expr<'tcx>) {
if matches!( let body = if let ExprKind::Closure(c) = expr.kind
callee.kind, && c.fn_decl.inputs.iter().all(|ty| matches!(ty.kind, TyKind::Infer))
ExprKind::Path(QPath::Resolved(..) | QPath::TypeRelative(..)) && matches!(c.fn_decl.output, FnRetTy::DefaultReturn(_))
) => && !expr.span.from_expansion()
{
cx.tcx.hir().body(c.body)
} else {
return;
};
if body.value.span.from_expansion() {
if body.params.is_empty() {
if let Some(VecArgs::Vec(&[])) = VecArgs::hir(cx, body.value) {
// replace `|| vec![]` with `Vec::new`
span_lint_and_sugg(
cx,
REDUNDANT_CLOSURE,
expr.span,
"redundant closure",
"replace the closure with `Vec::new`",
"std::vec::Vec::new".into(),
Applicability::MachineApplicable,
);
}
}
// skip `foo(|| macro!())`
return;
}
if is_adjusted(cx, body.value) {
return;
}
let typeck = cx.typeck_results();
let closure = if let ty::Closure(_, closure_subs) = typeck.expr_ty(expr).kind() {
closure_subs.as_closure()
} else {
return;
};
let closure_sig = cx.tcx.signature_unclosure(closure.sig(), Safety::Safe).skip_binder();
match body.value.kind {
ExprKind::Call(callee, args)
if matches!(
callee.kind,
ExprKind::Path(QPath::Resolved(..) | QPath::TypeRelative(..))
) =>
{
let callee_ty_raw = typeck.expr_ty(callee);
let callee_ty = callee_ty_raw.peel_refs();
if matches!(type_diagnostic_name(cx, callee_ty), Some(sym::Arc | sym::Rc))
|| !check_inputs(typeck, body.params, None, args)
{ {
let callee_ty_raw = typeck.expr_ty(callee); return;
let callee_ty = callee_ty_raw.peel_refs(); }
if matches!(type_diagnostic_name(cx, callee_ty), Some(sym::Arc | sym::Rc)) let callee_ty_adjusted = typeck
|| !check_inputs(typeck, body.params, None, args) .expr_adjustments(callee)
{ .last()
return; .map_or(callee_ty, |a| a.target.peel_refs());
}
let callee_ty_adjusted = typeck
.expr_adjustments(callee)
.last()
.map_or(callee_ty, |a| a.target.peel_refs());
let sig = match callee_ty_adjusted.kind() { let sig = match callee_ty_adjusted.kind() {
ty::FnDef(def, _) => { ty::FnDef(def, _) => {
// Rewriting `x(|| f())` to `x(f)` where f is marked `#[track_caller]` moves the `Location` // Rewriting `x(|| f())` to `x(f)` where f is marked `#[track_caller]` moves the `Location`
if cx.tcx.has_attr(*def, sym::track_caller) { if cx.tcx.has_attr(*def, sym::track_caller) {
return; return;
} }
cx.tcx.fn_sig(def).skip_binder().skip_binder() cx.tcx.fn_sig(def).skip_binder().skip_binder()
}, },
ty::FnPtr(sig) => sig.skip_binder(), ty::FnPtr(sig) => sig.skip_binder(),
ty::Closure(_, subs) => cx ty::Closure(_, subs) => cx
.tcx .tcx
.signature_unclosure(subs.as_closure().sig(), Safety::Safe) .signature_unclosure(subs.as_closure().sig(), Safety::Safe)
.skip_binder(), .skip_binder(),
_ => { _ => {
if typeck.type_dependent_def_id(body.value.hir_id).is_some() if typeck.type_dependent_def_id(body.value.hir_id).is_some()
&& let subs = typeck.node_args(body.value.hir_id) && let subs = typeck.node_args(body.value.hir_id)
&& let output = typeck.expr_ty(body.value) && let output = typeck.expr_ty(body.value)
&& let ty::Tuple(tys) = *subs.type_at(1).kind() && let ty::Tuple(tys) = *subs.type_at(1).kind()
{ {
cx.tcx.mk_fn_sig(tys, output, false, Safety::Safe, Abi::Rust) cx.tcx.mk_fn_sig(tys, output, false, Safety::Safe, Abi::Rust)
} else { } else {
return; return;
} }
}, },
}; };
if check_sig(cx, closure, sig) if let Some(outer) = outer_receiver
&& let generic_args = typeck.node_args(callee.hir_id) && ty_has_static(sig.output())
// Given some trait fn `fn f() -> ()` and some type `T: Trait`, `T::f` is not && let generic_args = typeck.node_args(outer.hir_id)
// `'static` unless `T: 'static`. The cast `T::f as fn()` will, however, result // HACK: Given a closure in `T.method(|| f())`, where `fn f() -> U where U: 'static`, `T.method(f)`
// in a type which is `'static`. // will succeed iff `T: 'static`. But the region of `T` is always erased by `typeck.expr_ty()` when
// For now ignore all callee types which reference a type parameter. // T is a generic type. For example, return type of `Option<String>::as_deref()` is a generic.
&& !generic_args.types().any(|t| matches!(t.kind(), ty::Param(_))) // So we have a hack like this.
{ && generic_args.len() > 0
span_lint_and_then(cx, REDUNDANT_CLOSURE, expr.span, "redundant closure", |diag| { {
if let Some(mut snippet) = snippet_opt(cx, callee.span) { return;
if path_to_local(callee).map_or(false, |l| { }
// FIXME: Do we really need this `local_used_in` check? if check_sig(closure_sig, sig)
// Isn't it checking something like... `callee(callee)`? && let generic_args = typeck.node_args(callee.hir_id)
// If somehow this check is needed, add some test for it, // Given some trait fn `fn f() -> ()` and some type `T: Trait`, `T::f` is not
// 'cuz currently nothing changes after deleting this check. // `'static` unless `T: 'static`. The cast `T::f as fn()` will, however, result
local_used_in(cx, l, args) || local_used_after_expr(cx, l, expr) // in a type which is `'static`.
}) { // For now ignore all callee types which reference a type parameter.
match cx.tcx.infer_ctxt().build().err_ctxt().type_implements_fn_trait( && !generic_args.types().any(|t| matches!(t.kind(), ty::Param(_)))
cx.param_env, {
Binder::bind_with_vars(callee_ty_adjusted, List::empty()), span_lint_and_then(cx, REDUNDANT_CLOSURE, expr.span, "redundant closure", |diag| {
ty::PredicatePolarity::Positive, if let Some(mut snippet) = snippet_opt(cx, callee.span) {
) { if path_to_local(callee).map_or(false, |l| {
// Mutable closure is used after current expr; we cannot consume it. // FIXME: Do we really need this `local_used_in` check?
Ok((ClosureKind::FnMut, _)) => snippet = format!("&mut {snippet}"), // Isn't it checking something like... `callee(callee)`?
Ok((ClosureKind::Fn, _)) if !callee_ty_raw.is_ref() => { // If somehow this check is needed, add some test for it,
snippet = format!("&{snippet}"); // 'cuz currently nothing changes after deleting this check.
}, local_used_in(cx, l, args) || local_used_after_expr(cx, l, expr)
_ => (), }) {
} match cx.tcx.infer_ctxt().build().err_ctxt().type_implements_fn_trait(
cx.param_env,
Binder::bind_with_vars(callee_ty_adjusted, List::empty()),
ty::PredicatePolarity::Positive,
) {
// Mutable closure is used after current expr; we cannot consume it.
Ok((ClosureKind::FnMut, _)) => snippet = format!("&mut {snippet}"),
Ok((ClosureKind::Fn, _)) if !callee_ty_raw.is_ref() => {
snippet = format!("&{snippet}");
},
_ => (),
} }
diag.span_suggestion(
expr.span,
"replace the closure with the function itself",
snippet,
Applicability::MachineApplicable,
);
} }
}); diag.span_suggestion(
} expr.span,
}, "replace the closure with the function itself",
ExprKind::MethodCall(path, self_, args, _) if check_inputs(typeck, body.params, Some(self_), args) => { snippet,
if let Some(method_def_id) = typeck.type_dependent_def_id(body.value.hir_id) Applicability::MachineApplicable,
&& !cx.tcx.has_attr(method_def_id, sym::track_caller) );
&& check_sig(cx, closure, cx.tcx.fn_sig(method_def_id).skip_binder().skip_binder()) }
{ });
span_lint_and_then( }
cx, },
REDUNDANT_CLOSURE_FOR_METHOD_CALLS, ExprKind::MethodCall(path, self_, args, _) if check_inputs(typeck, body.params, Some(self_), args) => {
expr.span, if let Some(method_def_id) = typeck.type_dependent_def_id(body.value.hir_id)
"redundant closure", && !cx.tcx.has_attr(method_def_id, sym::track_caller)
|diag| { && check_sig(closure_sig, cx.tcx.fn_sig(method_def_id).skip_binder().skip_binder())
let args = typeck.node_args(body.value.hir_id); {
let caller = self_.hir_id.owner.def_id; span_lint_and_then(
let type_name = get_path_from_caller_to_method_type(cx.tcx, caller, method_def_id, args); cx,
diag.span_suggestion( REDUNDANT_CLOSURE_FOR_METHOD_CALLS,
expr.span, expr.span,
"replace the closure with the method itself", "redundant closure",
format!("{}::{}", type_name, path.ident.name), |diag| {
Applicability::MachineApplicable, let args = typeck.node_args(body.value.hir_id);
); let caller = self_.hir_id.owner.def_id;
}, let type_name = get_path_from_caller_to_method_type(cx.tcx, caller, method_def_id, args);
); diag.span_suggestion(
} expr.span,
}, "replace the closure with the method itself",
_ => (), format!("{}::{}", type_name, path.ident.name),
} Applicability::MachineApplicable,
);
},
);
}
},
_ => (),
} }
} }
@ -251,12 +275,8 @@ fn check_inputs(
}) })
} }
fn check_sig<'tcx>(cx: &LateContext<'tcx>, closure: ClosureArgs<TyCtxt<'tcx>>, call_sig: FnSig<'_>) -> bool { fn check_sig<'tcx>(closure_sig: FnSig<'tcx>, call_sig: FnSig<'tcx>) -> bool {
call_sig.safety == Safety::Safe call_sig.safety == Safety::Safe && !has_late_bound_to_non_late_bound_regions(closure_sig, call_sig)
&& !has_late_bound_to_non_late_bound_regions(
cx.tcx.signature_unclosure(closure.sig(), Safety::Safe).skip_binder(),
call_sig,
)
} }
/// This walks through both signatures and checks for any time a late-bound region is expected by an /// This walks through both signatures and checks for any time a late-bound region is expected by an
@ -265,7 +285,7 @@ fn check_sig<'tcx>(cx: &LateContext<'tcx>, closure: ClosureArgs<TyCtxt<'tcx>>, c
/// This is needed because rustc is unable to late bind early-bound regions in a function signature. /// This is needed because rustc is unable to late bind early-bound regions in a function signature.
fn has_late_bound_to_non_late_bound_regions(from_sig: FnSig<'_>, to_sig: FnSig<'_>) -> bool { fn has_late_bound_to_non_late_bound_regions(from_sig: FnSig<'_>, to_sig: FnSig<'_>) -> bool {
fn check_region(from_region: Region<'_>, to_region: Region<'_>) -> bool { fn check_region(from_region: Region<'_>, to_region: Region<'_>) -> bool {
matches!(from_region.kind(), RegionKind::ReBound(..)) && !matches!(to_region.kind(), RegionKind::ReBound(..)) from_region.is_bound() && !to_region.is_bound()
} }
fn check_subs(from_subs: &[GenericArg<'_>], to_subs: &[GenericArg<'_>]) -> bool { fn check_subs(from_subs: &[GenericArg<'_>], to_subs: &[GenericArg<'_>]) -> bool {
@ -318,3 +338,8 @@ fn has_late_bound_to_non_late_bound_regions(from_sig: FnSig<'_>, to_sig: FnSig<'
.zip(to_sig.inputs_and_output) .zip(to_sig.inputs_and_output)
.any(|(from_ty, to_ty)| check_ty(from_ty, to_ty)) .any(|(from_ty, to_ty)| check_ty(from_ty, to_ty))
} }
fn ty_has_static(ty: Ty<'_>) -> bool {
ty.walk()
.any(|arg| matches!(arg.unpack(), GenericArgKind::Lifetime(re) if re.is_static()))
}

17
tests/ui/eta.fixed
View file

@ -2,6 +2,7 @@
#![allow(unused)] #![allow(unused)]
#![allow( #![allow(
clippy::needless_borrow, clippy::needless_borrow,
clippy::needless_option_as_deref,
clippy::needless_pass_by_value, clippy::needless_pass_by_value,
clippy::no_effect, clippy::no_effect,
clippy::option_map_unit_fn, clippy::option_map_unit_fn,
@ -482,3 +483,19 @@ mod issue_12853 {
x(); x();
} }
} }
mod issue_13073 {
fn get_default() -> Option<&'static str> {
Some("foo")
}
pub fn foo() {
// shouldn't lint
let bind: Option<String> = None;
let _field = bind.as_deref().or_else(|| get_default()).unwrap();
let bind: Option<&'static str> = None;
let _field = bind.as_deref().or_else(|| get_default()).unwrap();
// should lint
let _field = bind.or_else(get_default).unwrap();
}
}

17
tests/ui/eta.rs
View file

@ -2,6 +2,7 @@
#![allow(unused)] #![allow(unused)]
#![allow( #![allow(
clippy::needless_borrow, clippy::needless_borrow,
clippy::needless_option_as_deref,
clippy::needless_pass_by_value, clippy::needless_pass_by_value,
clippy::no_effect, clippy::no_effect,
clippy::option_map_unit_fn, clippy::option_map_unit_fn,
@ -482,3 +483,19 @@ mod issue_12853 {
x(); x();
} }
} }
mod issue_13073 {
fn get_default() -> Option<&'static str> {
Some("foo")
}
pub fn foo() {
// shouldn't lint
let bind: Option<String> = None;
let _field = bind.as_deref().or_else(|| get_default()).unwrap();
let bind: Option<&'static str> = None;
let _field = bind.as_deref().or_else(|| get_default()).unwrap();
// should lint
let _field = bind.or_else(|| get_default()).unwrap();
}
}

74
tests/ui/eta.stderr
View file

@ -1,5 +1,5 @@
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:29:27 --> tests/ui/eta.rs:30:27
| |
LL | let a = Some(1u8).map(|a| foo(a)); LL | let a = Some(1u8).map(|a| foo(a));
| ^^^^^^^^^^ help: replace the closure with the function itself: `foo` | ^^^^^^^^^^ help: replace the closure with the function itself: `foo`
@ -8,31 +8,31 @@ LL | let a = Some(1u8).map(|a| foo(a));
= help: to override `-D warnings` add `#[allow(clippy::redundant_closure)]` = help: to override `-D warnings` add `#[allow(clippy::redundant_closure)]`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:33:40 --> tests/ui/eta.rs:34:40
| |
LL | let _: Option<Vec<u8>> = true.then(|| vec![]); // special case vec! LL | let _: Option<Vec<u8>> = true.then(|| vec![]); // special case vec!
| ^^^^^^^^^ help: replace the closure with `Vec::new`: `std::vec::Vec::new` | ^^^^^^^^^ help: replace the closure with `Vec::new`: `std::vec::Vec::new`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:34:35 --> tests/ui/eta.rs:35:35
| |
LL | let d = Some(1u8).map(|a| foo((|b| foo2(b))(a))); //is adjusted? LL | let d = Some(1u8).map(|a| foo((|b| foo2(b))(a))); //is adjusted?
| ^^^^^^^^^^^^^ help: replace the closure with the function itself: `foo2` | ^^^^^^^^^^^^^ help: replace the closure with the function itself: `foo2`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:35:26 --> tests/ui/eta.rs:36:26
| |
LL | all(&[1, 2, 3], &&2, |x, y| below(x, y)); //is adjusted LL | all(&[1, 2, 3], &&2, |x, y| below(x, y)); //is adjusted
| ^^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `below` | ^^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `below`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:42:27 --> tests/ui/eta.rs:43:27
| |
LL | let e = Some(1u8).map(|a| generic(a)); LL | let e = Some(1u8).map(|a| generic(a));
| ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `generic` | ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `generic`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:94:51 --> tests/ui/eta.rs:95:51
| |
LL | let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo()); LL | let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo());
| ^^^^^^^^^^^ help: replace the closure with the method itself: `TestStruct::foo` | ^^^^^^^^^^^ help: replace the closure with the method itself: `TestStruct::foo`
@ -41,166 +41,172 @@ LL | let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo());
= help: to override `-D warnings` add `#[allow(clippy::redundant_closure_for_method_calls)]` = help: to override `-D warnings` add `#[allow(clippy::redundant_closure_for_method_calls)]`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:95:51 --> tests/ui/eta.rs:96:51
| |
LL | let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo()); LL | let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo());
| ^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `TestTrait::trait_foo` | ^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `TestTrait::trait_foo`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:97:42 --> tests/ui/eta.rs:98:42
| |
LL | let e = Some(&mut vec![1, 2, 3]).map(|v| v.clear()); LL | let e = Some(&mut vec![1, 2, 3]).map(|v| v.clear());
| ^^^^^^^^^^^^^ help: replace the closure with the method itself: `std::vec::Vec::clear` | ^^^^^^^^^^^^^ help: replace the closure with the method itself: `std::vec::Vec::clear`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:101:29 --> tests/ui/eta.rs:102:29
| |
LL | let e = Some("str").map(|s| s.to_string()); LL | let e = Some("str").map(|s| s.to_string());
| ^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `std::string::ToString::to_string` | ^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `std::string::ToString::to_string`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:102:27 --> tests/ui/eta.rs:103:27
| |
LL | let e = Some('a').map(|s| s.to_uppercase()); LL | let e = Some('a').map(|s| s.to_uppercase());
| ^^^^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `char::to_uppercase` | ^^^^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `char::to_uppercase`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:104:65 --> tests/ui/eta.rs:105:65
| |
LL | let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(|c| c.to_ascii_uppercase()).collect(); LL | let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(|c| c.to_ascii_uppercase()).collect();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `char::to_ascii_uppercase` | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `char::to_ascii_uppercase`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:167:22 --> tests/ui/eta.rs:168:22
| |
LL | requires_fn_once(|| x()); LL | requires_fn_once(|| x());
| ^^^^^^ help: replace the closure with the function itself: `x` | ^^^^^^ help: replace the closure with the function itself: `x`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:174:27 --> tests/ui/eta.rs:175:27
| |
LL | let a = Some(1u8).map(|a| foo_ptr(a)); LL | let a = Some(1u8).map(|a| foo_ptr(a));
| ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `foo_ptr` | ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `foo_ptr`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:179:27 --> tests/ui/eta.rs:180:27
| |
LL | let a = Some(1u8).map(|a| closure(a)); LL | let a = Some(1u8).map(|a| closure(a));
| ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `closure` | ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `closure`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:211:28 --> tests/ui/eta.rs:212:28
| |
LL | x.into_iter().for_each(|x| add_to_res(x)); LL | x.into_iter().for_each(|x| add_to_res(x));
| ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut add_to_res` | ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut add_to_res`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:212:28 --> tests/ui/eta.rs:213:28
| |
LL | y.into_iter().for_each(|x| add_to_res(x)); LL | y.into_iter().for_each(|x| add_to_res(x));
| ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut add_to_res` | ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut add_to_res`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:213:28 --> tests/ui/eta.rs:214:28
| |
LL | z.into_iter().for_each(|x| add_to_res(x)); LL | z.into_iter().for_each(|x| add_to_res(x));
| ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `add_to_res` | ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `add_to_res`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:220:21 --> tests/ui/eta.rs:221:21
| |
LL | Some(1).map(|n| closure(n)); LL | Some(1).map(|n| closure(n));
| ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut closure` | ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut closure`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:224:21 --> tests/ui/eta.rs:225:21
| |
LL | Some(1).map(|n| in_loop(n)); LL | Some(1).map(|n| in_loop(n));
| ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `in_loop` | ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `in_loop`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:317:18 --> tests/ui/eta.rs:318:18
| |
LL | takes_fn_mut(|| f()); LL | takes_fn_mut(|| f());
| ^^^^^^ help: replace the closure with the function itself: `&mut f` | ^^^^^^ help: replace the closure with the function itself: `&mut f`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:320:19 --> tests/ui/eta.rs:321:19
| |
LL | takes_fn_once(|| f()); LL | takes_fn_once(|| f());
| ^^^^^^ help: replace the closure with the function itself: `&mut f` | ^^^^^^ help: replace the closure with the function itself: `&mut f`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:324:26 --> tests/ui/eta.rs:325:26
| |
LL | move || takes_fn_mut(|| f_used_once()) LL | move || takes_fn_mut(|| f_used_once())
| ^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut f_used_once` | ^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut f_used_once`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:336:19 --> tests/ui/eta.rs:337:19
| |
LL | array_opt.map(|a| a.as_slice()); LL | array_opt.map(|a| a.as_slice());
| ^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `<[u8; 3]>::as_slice` | ^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `<[u8; 3]>::as_slice`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:339:19 --> tests/ui/eta.rs:340:19
| |
LL | slice_opt.map(|s| s.len()); LL | slice_opt.map(|s| s.len());
| ^^^^^^^^^^^ help: replace the closure with the method itself: `<[u8]>::len` | ^^^^^^^^^^^ help: replace the closure with the method itself: `<[u8]>::len`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:342:17 --> tests/ui/eta.rs:343:17
| |
LL | ptr_opt.map(|p| p.is_null()); LL | ptr_opt.map(|p| p.is_null());
| ^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `<*const usize>::is_null` | ^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `<*const usize>::is_null`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:346:17 --> tests/ui/eta.rs:347:17
| |
LL | dyn_opt.map(|d| d.method_on_dyn()); LL | dyn_opt.map(|d| d.method_on_dyn());
| ^^^^^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `<dyn TestTrait>::method_on_dyn` | ^^^^^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `<dyn TestTrait>::method_on_dyn`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:406:19 --> tests/ui/eta.rs:407:19
| |
LL | let _ = f(&0, |x, y| f2(x, y)); LL | let _ = f(&0, |x, y| f2(x, y));
| ^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `f2` | ^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `f2`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:434:22 --> tests/ui/eta.rs:435:22
| |
LL | test.map(|t| t.method()) LL | test.map(|t| t.method())
| ^^^^^^^^^^^^^^ help: replace the closure with the method itself: `Test::method` | ^^^^^^^^^^^^^^ help: replace the closure with the method itself: `Test::method`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:438:22 --> tests/ui/eta.rs:439:22
| |
LL | test.map(|t| t.method()) LL | test.map(|t| t.method())
| ^^^^^^^^^^^^^^ help: replace the closure with the method itself: `super::Outer::method` | ^^^^^^^^^^^^^^ help: replace the closure with the method itself: `super::Outer::method`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:451:18 --> tests/ui/eta.rs:452:18
| |
LL | test.map(|t| t.method()) LL | test.map(|t| t.method())
| ^^^^^^^^^^^^^^ help: replace the closure with the method itself: `test_mod::Test::method` | ^^^^^^^^^^^^^^ help: replace the closure with the method itself: `test_mod::Test::method`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:458:30 --> tests/ui/eta.rs:459:30
| |
LL | test.map(|t| t.method()) LL | test.map(|t| t.method())
| ^^^^^^^^^^^^^^ help: replace the closure with the method itself: `crate::issue_10854::d::Test::method` | ^^^^^^^^^^^^^^ help: replace the closure with the method itself: `crate::issue_10854::d::Test::method`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:477:38 --> tests/ui/eta.rs:478:38
| |
LL | let x = Box::new(|| None.map(|x| f(x))); LL | let x = Box::new(|| None.map(|x| f(x)));
| ^^^^^^^^ help: replace the closure with the function itself: `&f` | ^^^^^^^^ help: replace the closure with the function itself: `&f`
error: redundant closure error: redundant closure
--> tests/ui/eta.rs:481:38 --> tests/ui/eta.rs:482:38
| |
LL | let x = Box::new(|| None.map(|x| f(x))); LL | let x = Box::new(|| None.map(|x| f(x)));
| ^^^^^^^^ help: replace the closure with the function itself: `f` | ^^^^^^^^ help: replace the closure with the function itself: `f`
error: aborting due to 33 previous errors error: redundant closure
--> tests/ui/eta.rs:499:35
|
LL | let _field = bind.or_else(|| get_default()).unwrap();
| ^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `get_default`
error: aborting due to 34 previous errors