C++: Are const global variable array sizes part of the standard?

Question

https://code.sololearn.com/cnxo12V7EeFR/?ref=app
This is a challenge, and I think that although it compiles, it's not part of the iso standard.

Answer 1

Ace So you don't need a constexpr inside [] but a const which is known at compile time is enough?

Answer 2

Ace So it's not required by the standard?

Answer 3

Ace No, I'm asking if constexpr is required or if const is enough.

Answer 4

Thank you.