diff options
| -rw-r--r-- | src/librustc/middle/check_match.rs | 4 | ||||
| -rw-r--r-- | src/librustc/middle/pat_util.rs | 15 |
2 files changed, 18 insertions, 1 deletions
diff --git a/src/librustc/middle/check_match.rs b/src/librustc/middle/check_match.rs index 37f45142a11..9719460bbd3 100644 --- a/src/librustc/middle/check_match.rs +++ b/src/librustc/middle/check_match.rs @@ -879,7 +879,9 @@ pub fn check_legality_of_move_bindings(cx: &MatchCheckCtxt, let check_move: &fn(@pat, Option<@pat>) = |p, sub| { // check legality of moving out of the enum - if sub.is_some() { + + // x @ Foo(*) is legal, but x @ Foo(y) isn't. + if sub.map_move_default(false, |p| pat_contains_bindings(def_map, p)) { tcx.sess.span_err( p.span, "cannot bind by-move with sub-bindings"); diff --git a/src/librustc/middle/pat_util.rs b/src/librustc/middle/pat_util.rs index 9bf14697d9a..a67a488ef30 100644 --- a/src/librustc/middle/pat_util.rs +++ b/src/librustc/middle/pat_util.rs @@ -88,3 +88,18 @@ pub fn pat_binding_ids(dm: resolve::DefMap, pat: @pat) -> ~[NodeId] { pat_bindings(dm, pat, |_bm, b_id, _sp, _pt| found.push(b_id) ); return found; } + +/// Checks if the pattern contains any patterns that bind something to +/// an ident, e.g. `foo`, or `Foo(foo)` or `foo @ Bar(*)`. +pub fn pat_contains_bindings(dm: resolve::DefMap, pat: @pat) -> bool { + let mut contains_bindings = false; + do walk_pat(pat) |p| { + if pat_is_binding(dm, p) { + contains_bindings = true; + false // there's at least one binding, can short circuit now. + } else { + true + } + }; + contains_bindings +} |