Fix unarchiving empty containers.

[ginac.git] / ginac / expairseq.cpp

diff --git a/ginac/expairseq.cpp b/ginac/expairseq.cpp
index a1361532fc9994c7c920560f3893bca469aea286..59bd831620877496f71092145f006f1084a10f9e 100644 (file)
--- a/ginac/expairseq.cpp
+++ b/ginac/expairseq.cpp
@@ -112,17 +112,15 @@ expairseq::expairseq(epvector && vp, const ex &oc, bool do_index_renaming)
 void expairseq::read_archive(const archive_node &n, lst &sym_lst) 
 {
        inherited::read_archive(n, sym_lst);
-       auto first = n.find_first("rest");
-       auto last = n.find_last("coeff");
-       ++last;
-       seq.reserve((last-first)/2);
+       auto range = n.find_property_range("rest", "coeff");
+       seq.reserve((range.end-range.begin)/2);
 
-       for (auto loc = first; loc < last;) {
+       for (auto loc = range.begin; loc < range.end;) {
                ex rest;
                ex coeff;
                n.find_ex_by_loc(loc++, rest, sym_lst);
                n.find_ex_by_loc(loc++, coeff, sym_lst);
-               seq.push_back(expair(rest, coeff));
+               seq.emplace_back(expair(rest, coeff));
        }
 
        n.find_ex("overall_coeff", overall_coeff, sym_lst);