I think they're all ideas that are relatively obvious intuitive responses to the problem, and yet they may only incrase complexity tbh. For example, constexpr can be used relatively independent of template programming even, yet where they can be used practically before it becomes an unmaintainable mess of boilerplate are the most trivial cases, almost those which you could have hacked in with macros. TBF I think if you need serious metaprogramming, just compile and run a program at compile time.
Reflection has always been a mess no matter which implementation or language I've used. Fine for scripting languages, unusable for anything serious complex. The data you need is never there, and the data that is there is unusable, at the wrong semantic level (programming language level not what actually your own domain model semantics).
Also I avoid templates for the same reason, they're quickly becoming unmaintainable. Yes, I've tried to make use of them many times, and I have a fair number of them in deployed software. They work without bugs, of course. But I still don't love them, they're boilerplatey hard to maintain complexity that would be better solved with the right factoring plus a tiny bit of ad-hoc boilerplate. I would like to remove many of my deployed templates if I had the time.
And yes, I even avoid std:: template containers and such. Most uses I regret later. Again, this is for systems programming. They're fine for "scripting", leetcode, business software.
Is writing compilers, linkers, database servers, HPC and HFT platforms, OS drivers, networking stacks at IP level, considered systems programming accordign to you, or are they plain business software?
I said, I avoid, I don't love, I was talking about preference. And I'll state: Most of these are written mostly like I say. Please find serious counter-examples.
You must be talking about Linux, the BSDs, sqlite, postgres, gcc, the mold linker, or let's take some new kids on the block: raddebugger, FilePilot, TaskSlinger?
I am for example talking about LLVM and GCC, used to compile all those examples.
Living in the past? GCC has long adopted C++, last time it compiled with a pure C compiler was back in 2011 thereabouts, not cross-checking the exact year.
Reflection has always been a mess no matter which implementation or language I've used. Fine for scripting languages, unusable for anything serious complex. The data you need is never there, and the data that is there is unusable, at the wrong semantic level (programming language level not what actually your own domain model semantics).
Also I avoid templates for the same reason, they're quickly becoming unmaintainable. Yes, I've tried to make use of them many times, and I have a fair number of them in deployed software. They work without bugs, of course. But I still don't love them, they're boilerplatey hard to maintain complexity that would be better solved with the right factoring plus a tiny bit of ad-hoc boilerplate. I would like to remove many of my deployed templates if I had the time.
And yes, I even avoid std:: template containers and such. Most uses I regret later. Again, this is for systems programming. They're fine for "scripting", leetcode, business software.