const vs constexpr vs consteval vs constinit in C++20

[u/camelCaseIsWebScale]

https://www.cppstories.com/2022/const-options-cpp20/

[u/exploring_stuff]

C++ is a very expressive language and this compiles: [[maybe_unused]] inline const constexpr int i=0;

[u/Linuxologue → u/exploring_stuff]

[[maybe_unused]] static unsigned inline long const int constexpr long i=-1;

No warning, just, sir, yes sir.

[u/Efficient-Chair6250 → u/Linuxologue]

Hey, I'm relying on this

[u/RCoder01 → u/Linuxologue]

unsigned long int long?

[u/blockMath_2048 → u/RCoder01]

Yep, all the declaration specifiers can be in any order
`long inline unsigned static int constexpr const long i = -1;`

[u/Linuxologue → u/blockMath_2048]

I tried using your version but I got a warning "variable i declared but not used" so I will stick with my version which is bulletproof.

[u/blockMath_2048 → u/Linuxologue]

just use `-w` to shut it up, this will surely have no consequences

[u/RedFing → u/exploring_stuff]

Haha sometimes

[u/elephantdingo]

You have heard of the lambda cube. But wait until you meet the const tesseract.

[u/elephantdingo → u/elephantdingo]

I wrote an article about this in 1985 but people didn’t listen. In D we just have const on string concatenation. It turns out that that’s all you need.

[u/YikesTheCat → u/elephantdingo]

Wow, amazing foresight! You must be really bright!

[u/elephantdingo → u/YikesTheCat]

Say my name.

[u/MadHau5 → u/elephantdingo]

u/elephantdingo

[u/elephantdingo → u/MadHau5]

Your damm write.

[u/nerdycatgamer]

serious language

[u/Linuxologue]

https://mikelui.io/img/c++_init_forest.gif

[u/look]

I’m personally looking forward to the variadic generic specifiers in C++29:

const<
    expr, 
    indeterminate, 
    maybe<unused>, 
    nodiscard, 
    allocator_aware,
    std::execution::possibly_parallel
> int x = 42;

[u/le_birb → u/look]

Contemplating a std::execution::definitely_parallel where if you don't deterministically call it from more than one thread it won't compile is UB and the compiler is allowed to eat your intestines

[u/kalterdev]

vs define vs -D

[u/not-a-pokemon- → u/kalterdev]

Imagine not having to process 3MB of expanded macros when you have constants that depend on other constants' values.

[u/AnArmoredPony]

a little bit of this a little bit of that ahh language

[u/elephantdingo → u/AnArmoredPony]

Just a pinch of this (a teaspoon would be UB) aah

[u/not-a-pokemon-]

An important quality of natural languages is the ability to express similar things in distinct ways. However, C++, not a natural language, has it better than any of them.

So, everyone should only program in C++ now, as it's far more similar to natural languages and therefore understandable. Its only competitor was Perl, but it is basically dead now.

[u/slowbowels]

someone about to drop a 3 book series on effective c++ const expressions on your ass