uuid::repr_type is inaccessible

[tobias-loew]

The new internal data_type has the two public operators

        BOOST_CXX14_CONSTEXPR operator repr_type& () noexcept { return repr_; }
        constexpr operator repr_type const& () const noexcept { return repr_; }

but their return type repr_type is private and therefore inaccessible from outside.
As the operators are not used internally, I assume, they're to be used be users, so repr_type should also be public.

[pdimov]

repr_type is just an alias for std::uint8_t[16]. It's not intended to be named.

[tobias-loew]

Ok. But calling the user-defined conversion would then always require a typedef, since conversion-type-id does not allow array-brackets (https://en.cppreference.com/w/cpp/language/cast_operator).
IMHO, it would be nice also having functions (e.g. as_array()) returning a [const] reference to repr_.

[pdimov]

The conversion to repr_type& is an implementation detail, only intended to support old code that used data as a data member. So if you're using it to obtain access to the underlying array, it might indeed be better to provide a documented way to do that.

Out of curiosity, for what would you use this function?

[tobias-loew]

I've got a template-based serialization-library (not Boost.Serialization), which works out-of-the box, when it can deduce the full array-information (type and size). It used to work with code like ar & uuid_variable.data using Boost 1.85