- main_iter_ = src.main_iter_ ? src.main_iter_->clone () : 0;
- alternative_iter_ = src.alternative_iter_ ? src.alternative_iter_->clone () : 0;
- main_length_mom_ = src.main_length_mom_;
- if (main_iter_)
- scm_gc_unprotect_object (main_iter_->self_scm());
- if (alternative_iter_)
- scm_gc_unprotect_object (alternative_iter_->self_scm());