Merge #1733

1733: Parse arbitrarily complex `box` patterns. r=matklad a=ecstatic-morse

This fully resolves the pattern part of #1412 by enabling the parsing of complex `box` patterns such as:

```rust
let box Struct { box i, j: box Inner(box &x) } = todo!();
```

This introduces a new `ast::BoxPat` (in the mold of `ast::RefPat`) that gets translated to `hir::Pat::Missing`.

Co-authored-by: Dylan MacKenzie <[email protected]>

1 files changed, 5 insertions, 0 deletions

diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0143_box_pat.rs b/crates/ra_syntax/test_data/parser/inline/ok/0143_box_pat.rs
new file mode 100644
index 000000000..9d458aa1e
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0143_box_pat.rs
@@ -0,0 +1,5 @@
+fn main() {
+    let box i = ();
+    let box Outer { box i, j: box Inner(box &x) } = ();
+    let box ref mut i = ();
+}