関連ワード:  c++ remove from unordered_map    c++ remove from unordered_map while iterating    c++ delete from unordered_map    c++ erase from unordered_map    c++ remove element from unordered_map    c++ remove key from unordered_map    c++ remove entry from unordered_map    c++ delete element from unordered_map    c++ remove_if unordered_map    c++ erase_if unordered_map