I usually try to refrain from debates.....
I don't think it would have made much difference honestly, when people are blind sided with an attack out of nowhere (sucker punched as it were) with no warning of any kind it is difficult to be prepared or defend. Also the venues likely would not have allowed fire arms regardless.
I am PRO GUN and have several fire arms in my possession, I'm just saying that in this case I don't think it would make much difference.
Compare to the theater shooting here, no one was allowed to have a gun in that public venue, so everyone was unarmed and it had nothing to do with gun laws it was the rules of the establishment. That is probably why such a place was targeted by the coward in the first place. Gun "control" by the government is not always the problem, if all businesses would allow gun carry in their establishments there would not be many places considered "a sitting duck".
I do feel for the French people, these kind of attacks are cruel and senseless and loss of life is always felt. Hopefully they will wise up, USA seems to drag their feet on making any useful changes to keep terrorists out of the country.