Re: encapsulating directory operations

On 29/05/2025 14:38, Richard Heathfield wrote:

This really is a very simple point, but perhaps a simple analogy will help to clarify it. You don't throw out your 3/4" just because you've bought a 19mm. There is room for both in the toolbox, and why write 3/4" on your new spanner? It /isn't/ a 3/4" spanner even though it's very like it, so why pretend otherwise?
 

Your analogy does not cover C99 vs C90.
You have a good 3/4" spanner.  You don't throw it out just because you also get an adjustable spanner - sometimes the 3/4" spanner is more practical, or perhaps a bit stronger.  That's keeping C when you also have C++ available.
You have a good 3/4" spanner.  Now you get a new 3/4" spanner that is made of stronger steel, has a more comfortable grip, and has a box/ring at the other end which the old spanner did not.  You probably won't throw out the old spanner, but most of the time you will now use the new spanner.  That's C99 vs C90.
Sometimes, of course, we have non-rational reasons for a preference. Maybe you just like using the old spanner because you've had it since you were a kid and there's an emotional attachment.  Or maybe you don't like the shade of grey of the new spanner.  That, of course, is fine - when something is good enough for the job, you don't need something better and can make the choice for any other personal reason.  It is just very difficult for other people to understand such choices.