Merge branch 'cleanup/iterator' into 'master'
[cleanup] Remove warning about std::iterator.
See merge request !7 (merged)
(cherry picked from commit 4be4c85b)
41bc872c [cleanup] Remove warning about std::iterator. 5f70d15b [bugfix][ci] Fix headercheck in CI.
Co-authored-by: Robert K robertk@posteo.org