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

{%- set class_name = struct.name -%}
{%- set dtor_name = [] %}
{%- if struct|is_struct_with_handles %}
{%-   set _ = dtor_name.append("&internal::%s_Data_Destructor"|format(struct.name)) %}
{%- else %}
{%-   set _ = dtor_name.append("NULL") %}
{%- endif %}

{%- macro set_default(kind, value, depth) -%}
{#--- Strings ---#}
{%-   if kind|is_string_kind -%}
{{caller("mojo::String(" ~ value|expression_to_text(module) ~ ")")}}
{#--- Arrays ---#}
{%-   elif kind|is_array_kind %}
{%-     set _ = value|verify_token_type("ARRAY") %}
{
  {{kind|cpp_wrapper_type}}::Builder tmp{{depth}}({{value[1]|length}});
{%-     for element in value[1] %}
{%-       filter indent(2) %}
{%-         call(result) set_default(kind.kind, element, depth+1) %}
tmp{{depth}}[{{loop.index0}}] = {{result}};
{%-         endcall %}
{%-       endfilter %}
{%-     endfor -%}
  {{caller("tmp" ~ depth ~ ".Finish()")|indent(2)}}
}
{#--- Objects ---#}
{%-   elif kind|is_object_kind %}
{%-     set _ = value|verify_token_type("OBJECT") %}
{
  {{kind|cpp_wrapper_type}}::Builder tmp{{depth}};
{%-   set struct = kinds[kind.spec] %}
{%-   for element in value[1] %}
{#-     Use struct.packed_fields to order struct values by ordinal number #}
{%-     set subfield = struct.fields[loop.index0] %}
{%-     filter indent(2) %}
{%-       call(result) set_default(subfield.kind, element, depth+1) %}
tmp{{depth}}.set_{{subfield.name}}({{result}});
{%-       endcall %}
{%-     endfilter %}
{%-   endfor -%}
  {{caller("tmp" ~ depth ~ ".Finish()")|indent(2)}}
}
{#--- POD types ---#}
{%-   else -%}
{{caller(value|expression_to_text(module))}}
{%-   endif %}
{%- endmacro %}

{{class_name}}::Builder::Builder(mojo::Buffer* buf)
    : data_(Data::New(buf, {{dtor_name[0]}})) {
{%- for pf in struct.packed.packed_fields if pf.field.default %}
{%-   filter indent(2) %}
{%-     call(result) set_default(pf.field.kind, pf.field.default, 0) %}
set_{{pf.field.name}}({{result}});
{%-     endcall %}
{%-   endfilter %}
{%- endfor %}
}

{{class_name}} {{class_name}}::Builder::Finish() {
  Data* data = NULL;
  std::swap(data, data_);
  return mojo::internal::Wrap(data);
}