[Bug libstdc++/126604] [16/17 Regression] std::inclusive_scan moves from the first element of the input range

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126604

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I think we still want to use std::move(init) when passing it along, but should
do:

--- a/libstdc++-v3/include/std/numeric
+++ b/libstdc++-v3/include/std/numeric
@@ -583,7 +583,8 @@ namespace __detail
     {
       if (__first != __last)
        {
-         auto __init = _GLIBCXX_ITER_MOVE(__first);
+         typename iterator_traits<_InputIterator>::value_type __init
+           = *__first;
          *__result++ = __init;
          ++__first;
          if (__first != __last)