gcc 15 failure

[pgajdos]

Fails with gcc 15:

[   21s] + /usr/bin/cmake --build build -j8 -t check
[...]
[   67s] /home/abuild/rpmbuild/BUILD/zug-0.1.1-build/zug-0.1.1/zug/sequence.hpp:75:33: error: ‘struct zug::detail::sequence_data<ValueT, XformT>’ has no member named ‘impl’; did you mean ‘impl_’? [-Wtemplate-body]
[   67s]    75 |         impl_ = std::move(other.impl);
[   67s]       |                                 ^~~~
[   67s]       |                                 impl_
[   67s] gmake[3]: *** [test/CMakeFiles/test-sequence.dir/build.make:82: test/CMakeFiles/test-sequence.dir/sequence.cpp.o] Error 1

[pgajdos]

Also reported here:
https://bugs.gentoo.org/937320