Odd ellipsis in `constexpr_swap` in `include/boost/integer/common_factor_rt.hpp`

[stbergmann]

Recent GCC 15 trunk in C++26 mode now warns about

$ g++ -std=c++23 -fsyntax-only .../include/boost/integer/common_factor_rt.hpp
.../include/boost/integer/common_factor_rt.hpp:66:56: warning: omission of ‘,’ before varargs ‘...’ is deprecated in C++26 [-Wdeprecated-variadic-comma-omission]
   66 |          inline constexpr void constexpr_swap(T&a, U& b...) BOOST_GCD_NOEXCEPT(T)
      |                                                        ^~~
      |                                                        , 

And that ellipsis there, introduced in beb6871 "Switch over to using new Boost.Math version of gcd/lcm", looks more like a typo anyway?

[Lastique]

It's not a typo, I'm pretty sure it's there to disambiguate function overload resolution.