https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109229
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- e.g. https://en.cppreference.com/w/cpp/algorithm/accumulate is clear that the accumulator has the same type as the init parameter, and there's even a caveat about it: https://en.cppreference.com/w/cpp/algorithm/accumulate#Common_mistakes
