Add and parse unexposed entity

src/cpp_entity.cpp

@@ -4,10 +4,36 @@
 
 #include <cppast/cpp_entity.hpp>
 
+#include <cppast/cpp_entity_index.hpp>
 #include <cppast/cpp_entity_kind.hpp>
 
 using namespace cppast;
 
+cpp_entity_kind cpp_unexposed_entity::kind() noexcept
+{
+    return cpp_entity_kind::unexposed_t;
+}
+
+std::unique_ptr<cpp_entity> cpp_unexposed_entity::build(const cpp_entity_index& index,
+                                                        cpp_entity_id id, std::string name,
+                                                        std::string spelling)
+{
+    std::unique_ptr<cpp_entity> result(
+        new cpp_unexposed_entity(std::move(name), std::move(spelling)));
+    index.register_forward_declaration(id, type_safe::ref(*result));
+    return result;
+}
+
+std::unique_ptr<cpp_entity> cpp_unexposed_entity::build(std::string spelling)
+{
+    return std::unique_ptr<cpp_entity>(new cpp_unexposed_entity("", std::move(spelling)));
+}
+
+cpp_entity_kind cpp_unexposed_entity::do_get_entity_kind() const noexcept
+{
+    return kind();
+}
+
 bool cppast::is_templated(const cpp_entity& e) noexcept
 {
     if (!e.parent())