[Bug libstdc++/117187] New: __niter_base overloads need to be declare before use

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117187

            Bug ID: 117187
           Summary: __niter_base overloads need to be declare before use
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: redi at gcc dot gnu.org
  Target Milestone: ---

This fails to compile:

#include <iterator>
#include <algorithm>
#include <vector>

struct S { };

int main()
{
  std::vector<S> v;
  std::vector<S> out;
  std::copy(v.begin(), v.end(), std::make_move_iterator(vout.begin()));
}

The problem is that the __niter_wrap function calls std::__niter_base on the
move_iterator but the __niter_base(move_iterator<I>) overload has not been
declared at that point.