Investigate changing object_is_processed to std::set or std::unordered_set

[alanking]

Is there a reason that object_is_processed is a std::map and not a std::set (or std::unordered_set)? It seems like the value is always 1 (and only existence is checked for).

Originally posted by @FifthPotato in #295 (comment)

Relevant code:

irods_capability_storage_tiering/src/storage_tiering.cpp

Line 580 in 4c759d6

std::map<std::string, uint8_t> object_is_processed;