1 files changed, 32 insertions, 0 deletions
diff --git a/mojo/public/tools/bindings/generators/cpp_templates/struct_traits_declaration.tmpl b/mojo/public/tools/bindings/generators/cpp_templates/struct_traits_declaration.tmpl
new file mode 100644
index 0000000000..1b7cf8954b
--- /dev/null
+++ b/mojo/public/tools/bindings/generators/cpp_templates/struct_traits_declaration.tmpl
@@ -0,0 +1,32 @@
+{%- set mojom_type = struct|get_qualified_name_for_kind %}
+
+template <>
+struct {{export_attribute}} StructTraits<{{mojom_type}}::DataView,
+                                         {{mojom_type}}Ptr> {
+  static bool IsNull(const {{mojom_type}}Ptr& input) { return !input; }
+  static void SetToNull({{mojom_type}}Ptr* output) { output->reset(); }
+
+{%- for field in struct.fields %}
+{%-   set return_ref = field.kind|is_object_kind or
+  field.kind|is_any_handle_or_interface_kind %}
+{#    We want the field accessor to be const whenever possible to allow
+      structs to be used as map keys.
+      TODO(tibell): Make this check more precise to deal with e.g.
+          custom types which don't contain handles but require non-const
+          reference for serialization. #}
+{%-   set maybe_const = "" if field.kind|contains_handles_or_interfaces else "const" %}
+{%-   if return_ref %}
+  static {{maybe_const}} decltype({{mojom_type}}::{{field.name}})& {{field.name}}(
+      {{maybe_const}} {{mojom_type}}Ptr& input) {
+    return input->{{field.name}};
+  }
+{%-   else %}
+  static decltype({{mojom_type}}::{{field.name}}) {{field.name}}(
+      const {{mojom_type}}Ptr& input) {
+    return input->{{field.name}};
+  }
+{%-   endif %}
+{%- endfor %}
+
+  static bool Read({{mojom_type}}::DataView input, {{mojom_type}}Ptr* output);
+};