30 boost::container::small_vector<std::pair<size_type, size_type>, 128> entries(
32 std::sort(entries.begin(), entries.end());
33 boost::container::small_vector<size_type, 128> columns;
35 auto entry = entries.begin();
36 while (entry != entries.end())
38 const auto row = entry->first;
44 columns.reserve(
row_end - entry);
46 columns.push_back(entry->second);
50 if (columns.back() != entry->second)
51 columns.push_back(entry->second);