Implement unions as members of structs.

mojo/public/tools/bindings/generators/cpp_templates/struct_serialization_definition.tmpl

Index: mojo/public/tools/bindings/generators/cpp_templates/struct_serialization_definition.tmpl
diff --git a/mojo/public/tools/bindings/generators/cpp_templates/struct_serialization_definition.tmpl b/mojo/public/tools/bindings/generators/cpp_templates/struct_serialization_definition.tmpl
index 1612bbec9e571e4680dee6e0c06f7a1599915de8..dd9856bd75fd8c60e31c7ef93418a5aaaa88c65d 100644
--- a/mojo/public/tools/bindings/generators/cpp_templates/struct_serialization_definition.tmpl
+++ b/mojo/public/tools/bindings/generators/cpp_templates/struct_serialization_definition.tmpl
@@ -14,7 +14,10 @@ void Serialize_({{struct.name}}Ptr input, mojo::internal::Buffer* buf,
     internal::{{struct.name}}_Data* result =
         internal::{{struct.name}}_Data::New(buf);
 {%- for pf in struct.packed.packed_fields %}
-{%-   if pf.field.kind|is_object_kind %}
+{%-   if pf.field.kind|is_union_kind %}

[yzshen1, 2015/02/17 19:34:35]

It seems nicer to move this into the "is_object_kind" branch.

+      internal::{{pf.field.kind.name}}_Data* {{pf.field.name}}_ptr = &result->{{pf.field.name}};
+    Serialize_(mojo::internal::Forward(input->{{pf.field.name}}), buf, &{{pf.field.name}}_ptr);
+{%-   elif pf.field.kind|is_object_kind %}
 {%-     if pf.field.kind|is_array_kind %}
     mojo::SerializeArray_<{{pf.field.kind|get_array_validate_params|indent(26)}}>(
         mojo::internal::Forward(input->{{pf.field.name}}), buf, &result->{{pf.field.name}}.ptr);
@@ -57,7 +60,9 @@ void Deserialize_(internal::{{struct.name}}_Data* input,
   if (input) {
     {{struct.name}}Ptr result({{struct.name}}::New());
 {%- for pf in struct.packed.packed_fields %}
-{%-   if pf.field.kind|is_object_kind %}
+{%-   if pf.field.kind|is_union_kind %}
+    Deserialize_(&input->{{pf.field.name}}, &result->{{pf.field.name}});
+{%-   elif pf.field.kind|is_object_kind %}
     Deserialize_(input->{{pf.field.name}}.ptr, &result->{{pf.field.name}});
 {%-   elif pf.field.kind|is_interface_kind %}
     if (input->{{pf.field.name}}.is_valid())