Deprecated on 3.9: `tag_checker` used to be meant for cases where you've gotten an unsorted tag vector (mostly, from `get_tags_in_range`), which you then had to go through in parallel to your samples, to check which tag applies at what sample. For that it sorts the tags; the tags coming from the `get_tags*` functions are sorted already The checking pattern (which `chunks_to_symbols` is the last consumer of) is inefficient: instead of taking the index of the first unprocessed tag and processing all samples up to that index, a check is performed on every sample, which includes calls and multiple indirections. So, since very likely nobody uses this, and because it's a design anti-pattern, deprecating this on 3.9 and removing it with 3.10. Signed-off-by: Marcus Müller <mmueller@gnuradio.org>