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Change Rc<Box<T>> recommendation to be Rc<T> instead of Box<T>

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This commit is contained in:
JarredAllen 2020-08-11 18:01:10 -07:00
parent 439bae62a4
commit 480ccc3dbe
3 changed files with 15 additions and 4 deletions
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15
clippy_lints/src/types.rs
View File

@ -353,14 +353,25 @@ impl Types {
);
return; // don't recurse into the type
}
if let Some(span) = match_type_parameter(cx, qpath, &paths::BOX) {
if match_type_parameter(cx, qpath, &paths::BOX).is_some() {
let box_ty = match &last_path_segment(qpath).args.unwrap().args[0] {
GenericArg::Type(ty) => match &ty.kind {
TyKind::Path(qpath) => qpath,
_ => panic!("Box that isn't a type"),
},
_ => panic!("Rc without type argument"),
};
let inner_span = match &last_path_segment(&box_ty).args.unwrap().args[0] {
GenericArg::Type(ty) => ty.span,
_ => panic!("Box without type argument"),
};
span_lint_and_sugg(
cx,
REDUNDANT_ALLOCATION,
hir_ty.span,
"usage of `Rc<Box<T>>`",
"try",
snippet(cx, span, "..").to_string(),
format!("Rc<{}>", snippet(cx, inner_span, "..")),
Applicability::MachineApplicable,
);
return; // don't recurse into the type

2
tests/ui/redundant_allocation.fixed
View File

@ -33,7 +33,7 @@ pub fn test5(a: Rc<bool>) {}
// Rc<Box<T>>
pub fn test6(a: Box<bool>) {}
pub fn test6(a: Rc<bool>) {}
// Box<&T>

2
tests/ui/redundant_allocation.stderr
View File

@ -28,7 +28,7 @@ error: usage of `Rc<Box<T>>`
--> $DIR/redundant_allocation.rs:36:17
|
LL | pub fn test6(a: Rc<Box<bool>>) {}
| ^^^^^^^^^^^^^ help: try: `Box<bool>`
| ^^^^^^^^^^^^^ help: try: `Rc<bool>`
error: usage of `Box<&T>`
--> $DIR/redundant_allocation.rs:40:22