Stops temporary containers being created needlessly due to API misuse.
For example, it’s common for developers to assume QHash::values() and
QHash::keys() are free and abuse them, failing to realize their
implementation internally actually iterates the whole container, allocates
memory, and fills a new QList.
Added a removeIf generic algorithm, similar to std ones. We can't use std
algorithms with Qt dictionaries because Qt iterators have different
behavior from the std ones.
Found using clazy.
