From 5ccf8175a8ae5f6aaff30bb2330a5f05ec89028d Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Thu, 23 Aug 2012 17:02:41 -0700
Subject: [PATCH] don't consider use of `@fn` to be region-param'd

---
 src/rustc/middle/region.rs                    | 19 ++++++++++++++++
 .../regions-infer-at-fn-not-param.rs          | 22 +++++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 src/test/compile-fail/regions-infer-at-fn-not-param.rs

diff --git a/src/rustc/middle/region.rs b/src/rustc/middle/region.rs
index e9364e1762d..17d4eaa5984 100644
--- a/src/rustc/middle/region.rs
+++ b/src/rustc/middle/region.rs
@@ -655,6 +655,25 @@ fn determine_rp_in_ty(ty: @ast::ty,
       _ => {}
     }
 
+    // temporary hack: right now, fn() is short for &fn(), but @(fn())
+    // is `@fn()`, so catch this and set anon_implies_rp to none in
+    // that case
+    match ty.node {
+      ast::ty_box(mt) | ast::ty_uniq(mt) => {
+        match mt.ty.node {
+          ast::ty_fn(ast::proto_bare, _, _) |
+          ast::ty_fn(ast::proto_block, _, _) => {
+            do cx.with(cx.item_id, false) {
+                visit_mt(mt, cx, visitor);
+            }
+            return;
+          }
+          _ => {}
+        }
+      }
+      _ => {}
+    }
+
     match ty.node {
       ast::ty_box(mt) | ast::ty_uniq(mt) | ast::ty_vec(mt) |
       ast::ty_rptr(_, mt) | ast::ty_ptr(mt) => {
diff --git a/src/test/compile-fail/regions-infer-at-fn-not-param.rs b/src/test/compile-fail/regions-infer-at-fn-not-param.rs
new file mode 100644
index 00000000000..385372f5c43
--- /dev/null
+++ b/src/test/compile-fail/regions-infer-at-fn-not-param.rs
@@ -0,0 +1,22 @@
+struct param1 {
+    g: &fn();
+}
+
+struct param2 {
+    g: fn();
+}
+
+struct not_param1 {
+    g: @fn();
+}
+
+struct not_param2 {
+    g: @fn();
+}
+
+fn take1(p: param1) -> param1 { p } //~ ERROR mismatched types
+fn take2(p: param2) -> param2 { p } //~ ERROR mismatched types
+fn take3(p: not_param1) -> not_param1 { p }
+fn take4(p: not_param2) -> not_param2 { p }
+
+fn main() {}