Mojo C++ bindings: Merge EncodePointers/DecodePointers into Serialize/Deserialize, respectively.

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

 {#  TODO(yzshen): Make these templates more readable. #}
 
 {#  Computes the serialized size for the specified struct.
     |struct| is the struct definition.
     |input_field_pattern| should be a pattern that contains one string
     placeholder, for example, "input->%s", "p_%s". The placeholder will be
     substituted with struct field names to refer to the input fields.
     |context| is the name of the serialization context.
     |input_may_be_temp| indicates whether any input may be temporary obejcts.
     We need to assign temporary objects to local variables before passing it to
@@ skipping 42 matching lines @@
     |input_may_be_temp|: please see the comments of get_serialized_size.
     This macro is expanded to do serialization for both:
     - user-defined structs: the input is an instance of the corresponding struct
       wrapper class.
     - method parameters/response parameters: the input is a list of
       arguments. #}
 {%- macro serialize(struct, struct_display_name, input_field_pattern, output,
                     buffer, context, input_may_be_temp=False) -%}
   auto {{output}} =
       {{struct|get_qualified_name_for_kind(internal=True)}}::New({{buffer}});
+  ALLOW_UNUSED_LOCAL({{output}});
 {%- for pf in struct.packed.packed_fields_in_ordinal_order %}
 {%-   set input_field = input_field_pattern|format(pf.field.name) %}
 {%-   set name = pf.field.name %}
 {%-   set kind = pf.field.kind %}
 {%-   set serializer_type = kind|unmapped_type_for_serializer %}
 {%-   if kind|is_object_kind %}
 {%-     set original_input_field = input_field_pattern|format(name) %}
 {%-     set input_field = "in_%s"|format(name) if input_may_be_temp
                                                else original_input_field %}
 {%-     if input_may_be_temp %}
   decltype({{original_input_field}}) in_{{name}} = {{original_input_field}};
 {%-     endif %}
-
 {%-     if kind|is_array_kind or kind|is_map_kind %}
+  typename decltype({{output}}->{{name}})::BaseType* {{name}}_ptr;
   const mojo::internal::ContainerValidateParams {{name}}_validate_params(
       {{kind|get_container_validate_params_ctor_args|indent(10)}});
   mojo::internal::Serialize<{{serializer_type}}>(
-      {{input_field}}, {{buffer}}, &{{output}}->{{name}}.ptr,
-      &{{name}}_validate_params, {{context}});
+      {{input_field}}, {{buffer}}, &{{name}}_ptr, &{{name}}_validate_params,
+      {{context}});
+  {{output}}->{{name}}.Set({{name}}_ptr);
 {%-     elif kind|is_union_kind %}
   auto {{name}}_ptr = &{{output}}->{{name}};
   mojo::internal::Serialize<{{serializer_type}}>(
       {{input_field}}, {{buffer}}, &{{name}}_ptr, true, {{context}});
 {%-     else %}
+  typename decltype({{output}}->{{name}})::BaseType* {{name}}_ptr;
   mojo::internal::Serialize<{{serializer_type}}>(
-      {{input_field}}, {{buffer}}, &{{output}}->{{name}}.ptr, {{context}});
+      {{input_field}}, {{buffer}}, &{{name}}_ptr, {{context}});
+  {{output}}->{{name}}.Set({{name}}_ptr);
 {%-     endif %}
 {%-     if not kind|is_nullable_kind %}
   MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(
-{%-       if kind|is_union_kind %}
       {{output}}->{{name}}.is_null(),
-{%-       else %}
-      !{{output}}->{{name}}.ptr,
-{%-       endif %}
       mojo::internal::VALIDATION_ERROR_UNEXPECTED_NULL_POINTER,
       "null {{name}} in {{struct_display_name}}");
 {%-     endif %}
 
 {%-   elif kind|is_any_handle_or_interface_kind %}
   mojo::internal::Serialize<{{serializer_type}}>(
       {{input_field}}, &{{output}}->{{name}}, {{context}});
 {%-     if not kind|is_nullable_kind %}
   MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(
       !mojo::internal::IsHandleOrInterfaceValid({{output}}->{{name}}),
@@ skipping 37 matching lines @@
 {%-     if kind|is_object_kind or kind|is_enum_kind %}
   if (!{{input}}.Read{{name|under_to_camel}}(&{{output_field}}))
     {{success}} = false;
 {%-     elif kind|is_any_handle_or_interface_kind %}
   {{output_field}} = {{input}}.Take{{name|under_to_camel}}();
 {%-     else %}
   {{output_field}} = {{input}}.{{name}}();
 {%-     endif %}
 {%-   endfor %}
 {%- endmacro %}