Re: [boost] [review][fixed_string] End of review period approaching and a plea

Andrey Semashev wrote:

On 2019-12-04 18:24, Alexander Grund via Boost wrote:

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I would hope to see close to the same semantics as std::array, which I believe allows data() to return nullptr.

I don't think so:

"There is a special case for a zero-length array (|N == 0|). In that case, array.begin() == array.end(), which is some unique value. The effect of calling front() or back() on a zero-sized array is undefined." from https://en.cppreference.com/w/cpp/container/array

IMO this excludes nullptr as that won't be unique

I don't think iterators from different instances of a container are comparable. IOW, "unique" means distinct from any possible values of valid iterators obtained from this particular container instance.

That might not apply to pointers, though.

Pointers are comparable with ==, and array usually returns reinterpret_cast(this) from data() to satisfy the uniqueness requirement. Or used to return - I see that libstdc++ returns nullptr now, probably because reinterpret_cast can't be constexpr. https://github.com/gcc-mirror/gcc/blob/master/libstdc%2B%2B-v3/include/std/a...