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From: "giecrilj at stegny dot 2a.pl" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/50501] New: Insertion of complex into a stream may fail without invalidating the stream Date: Sat, 24 Sep 2011 00:35:00 -0000 [thread overview] Message-ID: <bug-50501-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50501 Bug #: 50501 Summary: Insertion of complex into a stream may fail without invalidating the stream Classification: Unclassified Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ AssignedTo: unassigned@gcc.gnu.org ReportedBy: giecrilj@stegny.2a.pl Host: x86_64-suse-linux Target: x86_64-suse-linux Build: x86_64-suse-linux I can see the following implementation in <complex>: /// Insertion operator for complex values. template<typename _Tp, typename _CharT, class _Traits> basic_ostream<_CharT, _Traits>& operator<<(basic_ostream<_CharT, _Traits>& __os, const complex<_Tp>& __x) { basic_ostringstream<_CharT, _Traits> __s; __s.flags(__os.flags()); __s.imbue(__os.getloc()); __s.precision(__os.precision()); __s << '(' << __x.real() << ',' << __x.imag() << ')'; // This can fail! return __os << __s.str(); // And then this may be empty! } This implementation may cause the following test case to fail: #include <cstdlib> #include <cassert> #include <iostream> #include <complex> int main () { float const a_f ((01)); ::std:: complex < float > a_c ((a_f)); std:: stringstream a_s; assert (!(a_s << a_c) || ((a_c = float ()) == float () && a_s >> a_c && a_c == a_f)); return +EXIT_SUCCESS; } I cannot reproduce the failure because I do not know how to inject a memory allocation failure. However, I imagine it is possible. I suggest that the implementation be modified: /// Insertion operator for complex values. template<typename _Tp, typename _CharT, class _Traits> basic_ostream<_CharT, _Traits>& operator<<(basic_ostream<_CharT, _Traits>& __os, const complex<_Tp>& __x) { basic_ostringstream<_CharT, _Traits> __s; __s.flags(__os.flags()); __s.imbue(__os.getloc()); __s.precision(__os.precision()); __s << '(' << __x.real() << ',' << __x.imag() << ')'; __os. setstate(__s.rdstate()) ; return __os << __s.str(); } Thank you for your consideration.
next reply other threads:[~2011-09-23 23:50 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-09-24 0:35 giecrilj at stegny dot 2a.pl [this message] 2011-09-24 4:12 ` [Bug libstdc++/50501] " paolo.carlini at oracle dot com 2011-09-24 4:25 ` redi at gcc dot gnu.org
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