Reusing bindings causes errors later in lowering:
```
error[E0596]: cannot borrow `vec` as mutable, as it is not declared as mutable
--> /checkout/src/test/ui/async-await/argument-patterns.rs:12:20
|
LL | async fn b(n: u32, ref mut vec: A) {
| ^^^^^^^^^^^
| |
| cannot borrow as mutable
| help: consider changing this to be mutable: `mut vec`
```
ident,
_,
) => (ident, true),
+ // For `ref mut` arguments, we can't reuse the binding, but
+ // we can keep the same name for the parameter.
+ // This lets rustdoc render it correctly in documentation.
+ hir::PatKind::Binding(_, _, ident, _) => (ident, false),
_ => {
// Replace the ident for bindings that aren't simple.
let name = format!("__arg{}", index);
'⚠'
}
+// @has async_fn/fn.mut_args.html '//pre[@class="rust fn"]' 'pub async fn mut_args(a: usize)'
+pub async fn mut_args(mut a: usize) {}
+
+// @has async_fn/fn.mut_ref.html '//pre[@class="rust fn"]' 'pub async fn mut_ref(x: i32)'
+pub async fn mut_ref(ref mut x: i32) {}
+
trait Bar {}
impl Bar for () {}
// @has async_fn/struct.Foo.html
// @matches - '//code' 'pub async fn f\(\)$'
// @matches - '//code' 'pub async unsafe fn g\(\)$'
+// @matches - '//code' 'pub async fn mut_self\(self, first: usize\)$'
pub struct Foo;
impl Foo {
pub async fn f() {}
pub async unsafe fn g() {}
+ pub async fn mut_self(mut self, mut first: usize) {}
}