Add forward declarations (#116)

src/CMakeLists.txt

@@ -44,6 +44,7 @@ set(header
     ../include/cppast/cpp_variable_template.hpp
     ../include/cppast/diagnostic.hpp
     ../include/cppast/diagnostic_logger.hpp
+    ../include/cppast/cppast_fwd.hpp
     ../include/cppast/libclang_parser.hpp
     ../include/cppast/parser.hpp
     ../include/cppast/visitor.hpp)

src/libclang/libclang_parser.cpp

@@ -494,6 +494,7 @@ namespace
 std::vector<const char*> get_arguments(const libclang_compile_config& config)
 {
     std::vector<const char*> args
+    // TODO: Why? and Why?
         = {"-x", "c++", "-I."}; // force C++ and enable current directory for include search
     for (auto& flag : detail::libclang_compile_config_access::flags(config))
         args.push_back(flag.c_str());

src/libclang/type_parser.cpp

@@ -99,6 +99,25 @@ bool need_to_remove_scope(const CXCursor& cur, const CXType& type)
 
 std::string get_type_spelling(const CXCursor& cur, const CXType& type)
 {
+    // TODO: There are two interesting things we should keep track of here:
+    // * The canonical name of a type (easy, clang has a shortcut for that)
+    // * The type definition of this type, say for:
+    //   std::vector<int, default_alloator...> this should be the type (we
+    //   should ignore specialization here!) vector<T, S> whose parent is a
+    //   namespace in this case but could again be a concrete type as well (to
+    //   handle nested type specializations correctly.)
+    /*
+    auto ns_name = [](const CXCursor& cur) {
+      auto parent = clang_getCursorSemanticParent(cur);
+      if (clang_getCursorKind(parent) == CXCursor_TranslationUnit)
+        return "";
+      if (clang_getCursorKind(parent) == CXCursor_Namespace)
+        return spelling of cursor ...
+    };
+    */
+
+    // auto canonical = detail::cxstring(clang_getTypeSpelling(clang_getCanonicalType(type))).std_str();
+    // auto declaration = detail::cxstring(clang_getCursorSpelling(clang_getTypeDeclaration(type))).std_str();
     auto spelling = detail::cxstring(clang_getTypeSpelling(type)).std_str();
     if (need_to_remove_scope(cur, type))
     {