Added checks for template specialization and out of bounds in template_arg_value

Author: nikhilshagri

src/clang.rs

@@ -457,8 +457,26 @@ impl Cursor {
     /// Given that this cursor's referent is a template specialization, and that
     /// the `i`th template argument is an integral, get the `i`th template
     /// argument value.
-    pub fn template_arg_value(&self, i: c_int) -> c_longlong {
-        unsafe { clang_Cursor_getTemplateArgumentValue(self.x, i as c_uint) }
+    pub fn template_arg_value(&self, i: c_int) -> Option<c_longlong> {
+        let within_bounds = match self.num_template_args() {
+            Some(num_args) => {
+                    if i > 0 && i < (num_args as i32) {
+                        true
+                    }
+                    else {
+                        false
+                    }
+                },
+            None => false
+        };
+        match within_bounds {
+            true => {
+                unsafe {
+                    Some(clang_Cursor_getTemplateArgumentValue(self.x, i as c_uint))
+                }
+            },
+            false => None
+        }
     }
 }