Their layout is problematic to match with regexes and changes often.

…ncmpcpp#652)

Co-authored-by: Devon Kirk <[email protected]>

…cmpcpp#654)

Co-authored-by: Devon Kirk <[email protected]>

libc++ 22 passes it[n] instead of *(it + n) to the comparator in std::sort.
For a non-POD value type, boost::transform_iterator returns a proxy object
from operator[]. Template argument deduction fails on the proxy, so the
templated overloads of LocaleBasedSorting::operator() do not match.

This is a libc++ bug, reported upstream as
llvm/llvm-project#223290. Until it is fixed,
replace boost::transform_iterator in NC::Menu with TransformIterator, which
returns a real reference from operator[].

Fixes ncmpcpp#663.