Description Dimitry Andric 2024-08-08 18:24:50 UTC

As noted in the libc++ 19 release notes [1], std::char_traits<> is now
only provided for char, char8_t, char16_t, char32_t and wchar_t, and any
instantiation for other types will fail.

This causes databases/mysql81-server to fail to compile with clang 19
and libc++ 19, resulting in errors similar to:

    /usr/include/c++/v1/string:820:42: error: implicit instantiation of undefined template 'std::char_traits<unsigned char>'
      820 |   static_assert(is_same<_CharT, typename traits_type::char_type>::value,
          |                                          ^
    /wrkdirs/usr/ports/databases/mysql81-client/work/mysql-8.1.0/sql/rpl_log_encryption.h:820:14: note: in instantiation of template class 'std::basic_string<unsigned char>' requested here
      820 |   Key_string m_encrypted_password;
          |              ^
    /usr/include/c++/v1/__fwd/string.h:23:29: note: template is declared here
       23 | struct _LIBCPP_TEMPLATE_VIS char_traits;
          |                             ^

`Key_string` is defined as `std::basic_string<unsigned char>`, which is
no longer possible. So redefine it as a `std::vector<unsigned char>`
instead.

This requires only a few small adjustments in other places: replacing
the `length()` method with the equivalent `size()` method, and adjusting
the arguments for the `assign()` method, which for `std::vector` takes a
begin and end iterator, instead of a begin iterator and a size.

[1] https://libcxx.llvm.org/ReleaseNotes/19.html#deprecations-and-removals