pub const PUBLISHER_GID_SIZE: usize = 24; // 24usizeExpand description
Size of the publisher Global Identifier (GID), in bytes.
24, which is upstream’s RMW_GID_STORAGE_SIZE — measured against Humble,
/opt/ros/humble/include/rmw/rmw/types.h:42 reads 24u — and the width of
the ABI’s own rmw_gid_t::data (RMW_GID_STORAGE_SIZE,
packages/core/nros-rmw-abi/include/nros/rmw_entity.h). So a gid read out of
a MessageInfo and a gid written by the get_gid_for_publisher vtable
slot are the same TYPE, comparable without a conversion.
It was 16 until the phase-467 RMW gap-closure design study’s Q1(a). The 16
is zenoh’s wire width, not a property of the identifier — see
MessageInfo::publisher_gid for what that leaves a reader owing.