Rollup merge of #33639 - petrochenkov:dotdot, r=nmatsakis

 cc https://github.com/rust-lang/rust/issues/33627
r? @nikomatsakis

plugin-[breaking-change] cc https://github.com/rust-lang/rust/issues/31645 @Manishearth

1 files changed, 22 insertions, 2 deletions

diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index dbef06f7aa4..5687099b27c 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -274,7 +274,10 @@ declare_features! (
     (active, drop_types_in_const, "1.9.0", Some(33156)),
 
     // Allows cfg(target_has_atomic = "...").
-    (active, cfg_target_has_atomic, "1.9.0", Some(32976))
+    (active, cfg_target_has_atomic, "1.9.0", Some(32976)),
+
+    // Allows `..` in tuple (struct) patterns
+    (active, dotdot_in_tuple_patterns, "1.10.0", Some(33627))
 );
 
 declare_features! (
@@ -315,7 +318,6 @@ declare_features! (
     // Allows `#[deprecated]` attribute
     (accepted, deprecated, "1.9.0", Some(29935))
 );
-
 // (changing above list without updating src/doc/reference.md makes @cmr sad)
 
 #[derive(PartialEq, Copy, Clone, Debug)]
@@ -1024,6 +1026,24 @@ impl<'a, 'v> Visitor<'v> for PostExpansionVisitor<'a> {
                                   pattern.span,
                                   "box pattern syntax is experimental");
             }
+            PatKind::Tuple(_, ddpos)
+                    if ddpos.is_some() => {
+                gate_feature_post!(&self, dotdot_in_tuple_patterns,
+                                  pattern.span,
+                                  "`..` in tuple patterns is experimental");
+            }
+            PatKind::TupleStruct(_, ref fields, ddpos)
+                    if ddpos.is_some() && !fields.is_empty() => {
+                gate_feature_post!(&self, dotdot_in_tuple_patterns,
+                                  pattern.span,
+                                  "`..` in tuple struct patterns is experimental");
+            }
+            PatKind::TupleStruct(_, ref fields, ddpos)
+                    if ddpos.is_none() && fields.is_empty() => {
+                self.context.span_handler.struct_span_err(pattern.span,
+                                                          "nullary enum variants are written with \
+                                                           no trailing `( )`").emit();
+            }
             _ => {}
         }
         visit::walk_pat(self, pattern)