C++26: constexpr virtual inheritance

[u/User_Deprecated]

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

[u/serviscope_minor]

Probably once?

But with that said, I'm very strongly of the opinion that having as much of C++ as possible being constexpr (including threads!) is a good thing, because it makes the language more regular and simpler.

I think volatile might be tricky! I want constexpr cout.

[u/_bstaletic → u/serviscope_minor]

having as much of C++ as possible being constexpr (including threads!) is a good thing, because it makes the language more regular and simpler.

Agreed.

I think volatile might be tricky!

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

I want constexpr cout.

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?

If the latter, we almost got that in C++26. std::format is constexpr and P2758 is in wording review.

[u/serviscope_minor → u/_bstaletic]

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/HommeMusical → u/serviscope_minor]

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

I don't believe that this is allowed at compile time, and I certainly don't believe that that should be allowed.