struct standard_metadata_t {
    // For more details see docs/simple_switch.md
    // in https://github.com/p4lang/behavioral-model

    // Should only read, ingress or egress
    bit<9>  ingress_port;
    bit<32> instance_type;
    bit<32> packet_length;
    bit<48> ingress_global_timestamp;
    bit<1>  checksum_error;
    error   parser_error;

    // In ingress, read or write.
    // In egress, should only read.
    bit<9>  egress_spec;
    bit<16> mcast_grp;

    // Should only read, only in egress
    bit<9>  egress_port;
    bit<16> egress_rid;
    bit<48> egress_global_timestamp;
    bit<32> enq_timestamp;
    bit<19> enq_qdepth;
    bit<32> deq_timedelta;
    bit<19> deq_qdepth;
}