But it also assumes that one smoker making an occasional visit's comfort does not overrule that of, say, 20 regulars enjoying not breathing in noxious fumes. Rather than expecting them all to cough and wheeze, the committed smoker could just choose another venue, too.

At the end of the day I would favour the option that does not have a measurable chemical impact on bystanders to the activity in question.

Mind you, now lots of pubs smell of toilet cleaner, damp and eau de old gent's wee instead of stale tobacco, which is not the greatest improvement.