Method set_error

include/exec/sequence/merge_each.hpp:580–586

      template <class _Error>
      void set_error(_Error&& __error) noexcept
      {
        auto __op = __op_;
        STDEXEC::set_stopped(static_cast<_NestedValueReceiver&&>(__nested_value_op_->__rcvr_));
        __op->store_error(static_cast<_Error&&>(__error));
        __op->nested_value_break();
      }

      void set_stopped() noexcept
      {