Add support for multiple region bounds in where clauses

6 files changed, 21 insertions, 14 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 13ea5da66c8..440e11e385f 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -430,11 +430,9 @@ pub struct WhereBoundPredicate {
 pub struct WhereRegionPredicate {
     pub span: Span,
     pub lifetime: Lifetime,
-    pub bound: Lifetime
+    pub bounds: Vec<Lifetime>,
 }
 
-impl Copy for WhereRegionPredicate {}
-
 #[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
 pub struct WhereEqPredicate {
     pub id: NodeId,
diff --git a/src/libsyntax/ext/deriving/generic/mod.rs b/src/libsyntax/ext/deriving/generic/mod.rs
index c40ccaa31a5..d8de3d2db97 100644
--- a/src/libsyntax/ext/deriving/generic/mod.rs
+++ b/src/libsyntax/ext/deriving/generic/mod.rs
@@ -435,7 +435,7 @@ impl<'a> TraitDef<'a> {
                     ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
                         span: self.span,
                         lifetime: rb.lifetime,
-                        bound: rb.bound
+                        bounds: rb.bounds.iter().map(|b| b.clone()).collect()
                     })
                 }
                 ast::WherePredicate::EqPredicate(ref we) => {
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index dd1e8b73f36..86df5883864 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -824,12 +824,12 @@ pub fn noop_fold_where_predicate<T: Folder>(
             })
         }
         ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{lifetime,
-                                                                       bound,
+                                                                       bounds,
                                                                        span}) => {
             ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
                 span: fld.new_span(span),
                 lifetime: fld.fold_lifetime(lifetime),
-                bound: fld.fold_lifetime(bound)
+                bounds: bounds.move_map(|bound| fld.fold_lifetime(bound))
             })
         }
         ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{id,
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 64bcf7dbdd1..f8b47e0405f 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -4199,9 +4199,8 @@ impl<'a> Parser<'a> {
 
                     self.eat(&token::Colon);
 
-                    // FIXME(#20049)
-                    let bounding_lifetime =
-                        self.parse_lifetime();
+                    let bounds =
+                        self.parse_lifetimes(token::BinOp(token::Plus));
 
                     let hi = self.span.hi;
                     let span = mk_sp(lo, hi);
@@ -4210,7 +4209,7 @@ impl<'a> Parser<'a> {
                         ast::WhereRegionPredicate {
                             span: span,
                             lifetime: bounded_lifetime,
-                            bound: bounding_lifetime
+                            bounds: bounds
                         }
                     ));
 
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index d619a386664..f27a476dbdd 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -2444,11 +2444,18 @@ impl<'a> State<'a> {
                     try!(self.print_bounds(":", bounds.as_slice()));
                 }
                 &ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{ref lifetime,
-                                                                                ref bound,
+                                                                                ref bounds,
                                                                                 ..}) => {
                     try!(self.print_lifetime(lifetime));
                     try!(word(&mut self.s, ":"));
-                    try!(self.print_lifetime(bound));
+
+                    for (i, bound) in bounds.iter().enumerate() {
+                        try!(self.print_lifetime(bound));
+
+                        if i != 0 {
+                            try!(word(&mut self.s, ":"));
+                        }
+                    }
                 }
                 &ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{ref path, ref ty, ..}) => {
                     try!(self.print_path(path, false));
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index c2a7a0316c7..9938feb171e 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -590,10 +590,13 @@ pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics
                 walk_ty_param_bounds_helper(visitor, bounds);
             }
             &ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{ref lifetime,
-                                                                            ref bound,
+                                                                            ref bounds,
                                                                             ..}) => {
                 visitor.visit_lifetime_ref(lifetime);
-                visitor.visit_lifetime_ref(bound);
+
+                for bound in bounds.iter() {
+                    visitor.visit_lifetime_ref(bound);
+                }
             }
             &ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{id,
                                                                     ref path,