Auto merge of #191 - glasserc:specialized-optional, r=emilio

Make clang::Cursor::specialized return an Option

Fixes #122.

pair=@Natim

Author: bors-servo

src/clang.rs

@@ -182,7 +182,7 @@ impl Cursor {
 
     /// Is the referent a template specialization?
     pub fn is_template(&self) -> bool {
-        self.specialized().is_valid()
+        self.specialized().is_some()
     }
 
     /// Is the referent a fully specialized template specialization without any
@@ -282,11 +282,12 @@ impl Cursor {
 
     /// Given that this cursor points to a template specialization, get a cursor
     /// pointing to the template definition that is being specialized.
-    pub fn specialized(&self) -> Cursor {
+    pub fn specialized(&self) -> Option<Cursor> {
         unsafe {
-            Cursor {
-                x: clang_getSpecializedCursorTemplate(self.x),
-            }
+            let ret = Cursor {
+                x: clang_getSpecializedCursorTemplate(self.x)
+            };
+            if ret.is_valid() { Some(ret) } else { None }
         }
     }
 

src/ir/comp.rs

@@ -512,7 +512,8 @@ impl CompInfo {
             }
         };
 
-        ci.ref_template = Item::parse(cursor.specialized(), None, ctx).ok();
+        ci.ref_template = cursor.specialized()
+            .and_then(|c| Item::parse(c, None, ctx).ok());
 
         let mut maybe_anonymous_struct_field = None;
         cursor.visit(|cur| {