Function likely

plugins/channel-safely/channel-groups.cpp:24–47

bool ChannelJobs::has_cavein_conditions(const df::coord &map_pos) {
    if likely(Maps::isValidTilePos(map_pos)) {
        auto p = map_pos;
        auto ttype = *Maps::getTileType(p);
        if (!DFHack::isOpenTerrain(ttype)) {
            // check shared neighbour for cave-in conditions
            df::coord neighbours[4];
            get_connected_neighbours(map_pos, neighbours);
            int connectedness = 4;
            for (auto n: neighbours) {
                if (!Maps::isValidTilePos(n) || active.count(n) || DFHack::isOpenTerrain(*Maps::getTileType(n))) {
                    connectedness--;
                }
            }
            if (!connectedness) {
                // do what?
                p.z--;
                if (!Maps::isValidTilePos(p)) return false;
                ttype = *Maps::getTileType(p);
                if (DFHack::isOpenTerrain(ttype) || DFHack::isFloorTerrain(ttype)) {
                    return true;
                }
            }
        }
    }
    return false;
}