Discussing the constness implied by various const keyword placements.
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It is known that declaration grammar in C/C++ can get pretty cryptic. But for reasons unknown to me, it is made even worse by introducing inconsistencies to the rules.
The position of the
const keyword is what I am thinking of. There is actually a pretty consistent way to declare things constant: It can be placed on the right of the thing that it qualifies as
int const x;
int const * const xp;
But C/C++ allows you to place that leftmost
const on the other side.
const int * const xp;
And unfortunately, that’s the popular (or even canonical, considering it being used in most texts) style. So I guess every newcomer starts by first learning the exception that doesn’t scale to more elaborate declarations, only to then relearn how to read things later.
Here is a good SO discussion about the general rule: What is the difference between const int*, const int * const, and int const *?. It links to a few other useful pages as well.
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