[Interest] Mac: a bit of 10.9 love

[René J. V. Bertin]

> I am curious to find out just how many customers of your application
> there are that are _still_ on macOS 10.9?

> Even if it is just a few why are you letting just a few customers hold
> you back from using newer compilers, versions of C++, newer tools. [...]

In fact it's I myself who doesn't like to waste time applying disruptive OS 
updates and figuring out how to get everything to work again like I want it (or 
discover that my 6 yo MBP really isn't that well suited to run the latest and 
supposedly greatest). I rarely use Xcode so I'm free to install and use the 
newest compilers and other tools.

Either way, this was not the kind of discussion I intended to spawn so I'll 
leave it at that ...

R.