static void pb_field_set_to_default(pb_field_iter_t *iter)
{
    pb_type_t type;
    type = iter->pos->type;
    
    if (PB_LTYPE(type) == PB_LTYPE_EXTENSION)
    {
        pb_extension_t *ext = *(pb_extension_t* const *)iter->pData;
        while (ext != NULL)
        {
            pb_field_iter_t ext_iter;
            ext->found = false;
            iter_from_extension(&ext_iter, ext);
            pb_field_set_to_default(&ext_iter);
            ext = ext->next;
        }
    }
    else if (PB_ATYPE(type) == PB_ATYPE_STATIC)
    {
        bool init_data = true;
        if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL && iter->pSize != iter->pData)
        {
            /* Set has_field to false. Still initialize the optional field
             * itself also. */
            *(bool*)iter->pSize = false;
        }
        else if (PB_HTYPE(type) == PB_HTYPE_REPEATED ||
                 PB_HTYPE(type) == PB_HTYPE_ONEOF)
        {
            /* REPEATED: Set array count to 0, no need to initialize contents.
               ONEOF: Set which_field to 0. */
            *(pb_size_t*)iter->pSize = 0;
            init_data = false;
        }

        if (init_data)
        {
            if (PB_LTYPE(iter->pos->type) == PB_LTYPE_SUBMESSAGE)
            {
                /* Initialize submessage to defaults */
                pb_message_set_to_defaults((const pb_field_t *) iter->pos->ptr, iter->pData);
            }
            else if (iter->pos->ptr != NULL)
            {
                /* Initialize to default value */
                memcpy(iter->pData, iter->pos->ptr, iter->pos->data_size);
            }
            else
            {
                /* Initialize to zeros */
                memset(iter->pData, 0, iter->pos->data_size);
            }
        }
    }
    else if (PB_ATYPE(type) == PB_ATYPE_POINTER)
    {
        /* Initialize the pointer to NULL. */
        *(void**)iter->pData = NULL;
        
        /* Initialize array count to 0. */
        if (PB_HTYPE(type) == PB_HTYPE_REPEATED ||
            PB_HTYPE(type) == PB_HTYPE_ONEOF)
        {
            *(pb_size_t*)iter->pSize = 0;
        }
    }
    else if (PB_ATYPE(type) == PB_ATYPE_CALLBACK)
    {
        /* Don't overwrite callback */
    }
}
static void pb_field_set_to_default(pb_field_iter_t *iter)
{
    pb_type_t type;
    type = iter->pos->type;
    
    if (PB_LTYPE(type) == PB_LTYPE_EXTENSION)
    {
        pb_extension_t *ext = *(pb_extension_t* const *)iter->pData;
        while (ext != NULL)
        {
            pb_field_iter_t ext_iter;
            ext->found = false;
            iter_from_extension(&ext_iter, ext);
            pb_field_set_to_default(&ext_iter);
            ext = ext->next;
        }
    }
    else if (PB_ATYPE(type) == PB_ATYPE_STATIC)
    {
        bool init_data = true;
        if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL && iter->pSize != iter->pData)
        {
             
            *(bool*)iter->pSize = false;
        }
        else if (PB_HTYPE(type) == PB_HTYPE_REPEATED ||
                 PB_HTYPE(type) == PB_HTYPE_ONEOF)
        {
             
            *(pb_size_t*)iter->pSize = 0;
            init_data = false;
        }

        if (init_data)
        {
            if (PB_LTYPE(iter->pos->type) == PB_LTYPE_SUBMESSAGE)
            {
                 
                pb_message_set_to_defaults((const pb_field_t *) iter->pos->ptr, iter->pData);
            }
            else if (iter->pos->ptr != NULL)
            {
                 
                memcpy(iter->pData, iter->pos->ptr, iter->pos->data_size);
            }
            else
            {
                 
                memset(iter->pData, 0, iter->pos->data_size);
            }
        }
    }
    else if (PB_ATYPE(type) == PB_ATYPE_POINTER)
    {
         
        *(void**)iter->pData = NULL;
        
         
        if (PB_HTYPE(type) == PB_HTYPE_REPEATED ||
            PB_HTYPE(type) == PB_HTYPE_ONEOF)
        {
            *(pb_size_t*)iter->pSize = 0;
        }
    }
    else if (PB_ATYPE(type) == PB_ATYPE_CALLBACK)
    {
         
    }
}