I'm just getting one big line, no CRLF in the archive. Makes it difficult to debug. Interesting thing is that I was seeing CRLF in a previous archive I created in another app. There is no difference I can detect in the way I'm archiving in this app. Tool chain ... g++ (GCC) 4.9.2 20150212 (Red Hat 4.9.2-6) libstdc++-4.9.2-6.fc21.x86_64 libstdc++-devel-4.9.2-6.fc21.x86_64 Code... typedef std::multimap<unsigned, int> cnodemap_t; typedef cnodemap_t::value_type cnpair_t; typedef cnodemap_t::iterator cniterator_t; typedef std::multimap<unsigned, qnode> qnodemap_t; typedef qnodemap_t::value_type qnpair_t; typedef qnodemap_t::iterator qniterator_t; typedef qnodemap_t::reverse_iterator qnriterator_t; struct qnode { qnode(){} enum ctlflags flags; std::string sname; std::string stypnam; std::string sdecl; cnodemap_t parents; cnodemap_t children; template<class Archive> void serialize(Archive &ar, const unsigned int version) { if (version){;} ar & flags & sdecl & sname & parents & children; } }; class Cqnodemap { public: Cqnodemap(){} qnodemap_t qnmap; template<class Archive> void serialize(Archive &ar, const unsigned int version) { if (version){;} ar & qnmap; } }; static inline void write_cqnmap(const char *filename, Cqnodemap& cqnmap) { ofstream ofs(filename, ofstream::out | ofstream::app); if (!ofs.is_open()) { cout << "Cannot open file: " << filename << endl; exit(1); } { boost::archive::text_oarchive oa(ofs); oa << cqnmap; } ofs.close(); }