/// **What it does:** Detects passing a mutable reference to a function that only
/// requires an immutable reference.
///
- /// **Why is this bad?** The immutable reference rules out all other references
- /// to the value. Also the code misleads about the intent of the call site.
+ /// **Why is this bad?** The mutable reference rules out all other references to
+ /// the value. Also the code misleads about the intent of the call site.
///
/// **Known problems:** None.
///
arguments,
cx.typeck_results().expr_ty(fn_expr),
&rustc_hir_pretty::to_string(rustc_hir_pretty::NO_ANN, |s| s.print_qpath(path, false)),
+ "function",
);
}
},
let def_id = cx.typeck_results().type_dependent_def_id(e.hir_id).unwrap();
let substs = cx.typeck_results().node_substs(e.hir_id);
let method_type = cx.tcx.type_of(def_id).subst(cx.tcx, substs);
- check_arguments(cx, arguments, method_type, &path.ident.as_str())
+ check_arguments(cx, arguments, method_type, &path.ident.as_str(), "method")
},
_ => (),
}
}
}
-fn check_arguments<'tcx>(cx: &LateContext<'tcx>, arguments: &[Expr<'_>], type_definition: Ty<'tcx>, name: &str) {
- match type_definition.kind {
+fn check_arguments<'tcx>(
+ cx: &LateContext<'tcx>,
+ arguments: &[Expr<'_>],
+ type_definition: Ty<'tcx>,
+ name: &str,
+ fn_kind: &str,
+) {
+ match type_definition.kind() {
ty::FnDef(..) | ty::FnPtr(_) => {
let parameters = type_definition.fn_sig(cx.tcx).skip_binder().inputs();
for (argument, parameter) in arguments.iter().zip(parameters.iter()) {
- match parameter.kind {
+ match parameter.kind() {
ty::Ref(_, _, Mutability::Not)
| ty::RawPtr(ty::TypeAndMut {
mutbl: Mutability::Not, ..
cx,
UNNECESSARY_MUT_PASSED,
argument.span,
- &format!("The function/method `{}` doesn't need a mutable reference", name),
+ &format!("the {} `{}` doesn't need a mutable reference", fn_kind, name),
);
}
},