const is different in C++ from const in C. const variables in C++ are proper compile-time constants. In C they are not (the nearest equivalents are #define and enum values).
So in C++ "const x = EXPR" would make sense to request compile-time evaluation, but in C it wouldn't.
Ouch, but thanks. I learned something today - something I'd long forgotten. I like your example, it shows the point well. (Though, there are circumstances when a compiler can unroll such a loop and infer a compile-time constant, it wouldn't qualify as a constant expression at the language level.)
It's been so long since I used C++ for serious work that we weren't using C++11, so neither auto nor range-for were available. It would be uncommon to see "const type = " with a non-reference type and a non-constant initialiser.
Even with your example, some styles avoid "const auto item", using either "auto item" or "const auto& item" instead, because the "const" matters when taking a reference, not so much with a copy.
But I appreciate your point applies to const variables with non-constant initialisers in general, in the language.
There was once a big deal in literature about const in C++ being the "better" alternative to how #define is commonly used with C for constant values, and it seemed applicable to the thread as a key distinction between C and C++, which the parent commenter seemed to have conflated by mistake.
But I'd forgotten about const (non-reference) variables accepting non-constant initialisers, and as I hadn't used C++ seriously in a while, and the language is always changing, I checked in with a couple of C++ tutorials before writing. Unfortunately those tutorials were misleading or too simple, as both tutoruals said nothing about "const type x = " (non-reference/pointer) being uwed in any other way than for defining compile-time constants.
It's bit embarrssing, as I read other parts of the C++ standard quite often despite not using it much these days. (I'm into compiler guts, atomics, memory models, code analysis, portability issues, etc.). Yet I had forgotten this part of the language.
So, thanks for sending me down a learning & reminder rabbit-hole and correcting my error :-)
So in C++ "const x = EXPR" would make sense to request compile-time evaluation, but in C it wouldn't.