https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93562
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:9962493ca2f71d3f3dd06b0e9cd19fcf849e3e4b commit r10-6431-g9962493ca2f71d3f3dd06b0e9cd19fcf849e3e4b Author: Jonathan Wakely <jwak...@redhat.com> Date: Tue Feb 4 12:59:14 2020 +0000 libstdc++: Fix regressions in unique_ptr::swap (PR 93562) The requirements for this function are only that the deleter is swappable, but we incorrectly require that the element type is complete and that the deleter can be swapped using std::swap (which requires it to be move cosntructible and move assignable). The fix is to add __uniq_ptr_impl::swap which swaps the pointer and deleter individually, instead of using the generic std::swap on the tuple containing them. PR libstdc++/93562 * include/bits/unique_ptr.h (__uniq_ptr_impl::swap): Define. (unique_ptr::swap, unique_ptr<T[], D>::swap): Call it. * testsuite/20_util/unique_ptr/modifiers/93562.cc: New test.