Support parenthesized paths `Foo(A,B) -> C` that expand to `Foo<(A,B),C>`. These paths also bind anonymous regions (or will, once HRTB is fully working).

Fixes #18423.

1 files changed, 5 insertions, 4 deletions

diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index dc4eaf7d7ad..5921d630b89 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -313,14 +313,15 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
                                                       .map(|ident| {
             ast::PathSegment {
                 identifier: ident,
-                lifetimes: Vec::new(),
-                types: OwnedSlice::empty(),
+                parameters: ast::PathParameters::none(),
             }
         }).collect();
         segments.push(ast::PathSegment {
             identifier: last_identifier,
-            lifetimes: lifetimes,
-            types: OwnedSlice::from_vec(types),
+            parameters: ast::AngleBracketedParameters(ast::AngleBracketedParameterData {
+                lifetimes: lifetimes,
+                types: OwnedSlice::from_vec(types),
+            })
         });
         ast::Path {
             span: sp,