Auto merge of #194 - emilio:template-args, r=fitzgen

clang: Some partially specialized templates return no template argument count.

Trying to construct a test case, meanwhile: r? @fitzgen

Author: bors-servo

src/clang.rs

@@ -131,6 +131,9 @@ impl Cursor {
     /// Return the number of template arguments used by this cursor's referent,
     /// if the referent is either a template specialization or
     /// declaration. Returns -1 otherwise.
+    ///
+    /// NOTE: This may not return `Some` for some non-fully specialized
+    /// templates, see #193 and #194.
     pub fn num_template_args(&self) -> Option<u32> {
         let n: c_int = unsafe { clang_Cursor_getNumTemplateArguments(self.x) };
 
@@ -193,7 +196,7 @@ impl Cursor {
     /// Is the referent a fully specialized template specialization without any
     /// remaining free template arguments?
     pub fn is_fully_specialized_template(&self) -> bool {
-        self.is_template() && self.num_template_args().unwrap() > 0
+        self.is_template() && self.num_template_args().unwrap_or(0) > 0
     }
 
     /// Is the referent a template specialization that still has remaining free

tests/expectations/base-to-derived.rs

@@ -0,0 +1,19 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(non_snake_case)]
+
+
+#[repr(C)]
+#[derive(Debug, Copy)]
+pub struct false_type {
+    pub _address: u8,
+}
+#[test]
+fn bindgen_test_layout_false_type() {
+    assert_eq!(::std::mem::size_of::<false_type>() , 1usize);
+    assert_eq!(::std::mem::align_of::<false_type>() , 1usize);
+}
+impl Clone for false_type {
+    fn clone(&self) -> Self { *self }
+}

tests/headers/base-to-derived.hpp

@@ -0,0 +1,19 @@
+// bindgen-flags: -- -std=c++11
+
+struct false_type {};
+
+template<typename _From, typename _To, bool>
+struct __is_base_to_derived_ref;
+
+template<typename _From, typename _To>
+struct __is_base_to_derived_ref<_From, _To, true>
+{
+  typedef _To type;
+
+  static constexpr bool value = type::value;
+};
+
+template<typename _From, typename _To>
+struct __is_base_to_derived_ref<_From, _To, false>
+: public false_type
+{ };