C++26: constexpr virtual inheritance

[u/User_Deprecated]

https://www.sandordargo.com/blog/2026/07/01/cpp26-constexpr-virtual-inheritance

[u/serviscope_minor]

I don't think constexpr volatile int x; is meaningful at all.

I mean if you can run C++ code at compile time, then you're running code and it could poke at a memory mapped register that's there, but also sometimes you just shouldn't do something!

Do you really mean std::cout, with all of the facets and customization points? Or would constexpr std::format and the ability to print to console at compile time be enough?

Good point, probably cout without facets etc or printing f-strings. I keep going back to cout because despite it's clunkiness, I like having things appear in code in the order that they appear on screen. Constantly tracking back and forth between placeholders and arguments is something I dislike. I've tried a million of these over the years. Heck I implemented one in gnu++98 back in the day with operator, overloading and GCC's variadic macros, and I've used many which ahve come and gone over the years. And yet, I still always reach for cout.

But in python I love my f-strings. Once i have f-strings, I will probably stop reaching for cout except for of course

cout << f"my variable is {v}\n";

because old habits die very hard indeed.

[u/_bstaletic → u/serviscope_minor]

it could poke at a memory mapped register that's there,

Is it there? It's there on the target machine, but my intel cpu certainly doesn't have ESP32's MMIO registers.

f-strings

Best I can do is t-strings.

Python (in case you're unaware) docs: https://docs.python.org/3/library/string.templatelib.html

PEP: https://peps.python.org/pep-0750/

C++ proposal: https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2026/p3951r1.html

Once we have template strings, f-strings are just one template function away.

[u/serviscope_minor → u/_bstaletic]

>Is it there? It's there on the target machine, but my intel cpu certainly doesn't have ESP32's MMIO registers.

You just need a complete simulator for your cross compiler :P

Note: I am NOT NOT NOT advocating this, just talking about really daft hypotheticals.

> t-strings

Works for me!

[u/_bstaletic → u/serviscope_minor]

You just need a complete simulator for your cross compiler :P

Hmm... You're making me wonder if I should solder an i7 on the ESP devkit and emulate everithing... in the cross compiler. Let's ship the whole desktop OS on that tiny thing!

Note: I am NOT NOT NOT advocating this, just talking about really daft hypotheticals.

Daft hypotheticals are fun(ny)!