[Bug libstdc++/34524] New: Use of invalidated std::string iterators not caught in debug mode

[Bug libstdc++/34524] New: Use of invalidated std::string iterators not caught in debug mode

[gcc-bugzilla at contacts dot eelis dot net]

In the following code, libstdc++'s debug mode does not catch the use of a
potentially invalidated std::string iterator.

  #define _GLIBCXX_DEBUG
  #define _GLIBCXX_DEBUG_PEDANTIC

  #include <string>
  #include <vector>
  #include <iostream>

  int main()
  {
    typedef std::string S;

    S s (3, 'x');
    S::iterator i = s.begin(); ++i;
    s.push_back('y');
    std::cout << *i << std::endl; // just outputs 'x'
  }

Since the push_back may invalidate i (per 21.3 para 5, 4th item), libstdc++'s
debug mode should emit an error and abort.

If I change the typedef to std::vector<char>, then the indicated line /does/
cause libstdc++ to emit an error ("attempt to dereference a singular iterator")
and abort.


-- 
           Summary: Use of invalidated std::string iterators not caught in
                    debug mode
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: gcc-bugzilla at contacts dot eelis dot net


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34524

[Bug libstdc++/34524] Use of invalidated std::string iterators not caught in debug mode

[pcarlini at suse dot de]

------- Comment #1 from pcarlini at suse dot de  2007-12-18 20:00 -------
Did you read the documentation?

  http://gcc.gnu.org/onlinedocs/libstdc++/ext/debug_mode.html

in a nutshell, our design doesn't provide safe iterators for basic_string.


-- 

pcarlini at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |WONTFIX


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34524

[Bug libstdc++/34524] Use of invalidated std::string iterators not caught in debug mode

[gcc-bugzilla at contacts dot eelis dot net]

------- Comment #2 from gcc-bugzilla at contacts dot eelis dot net  2007-12-18 20:16 -------
My apologies.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34524