source: https://sourceware.org/gdb/wiki/STLSupport use GDB's "print" command to display the contents of a vector, a stack, or any other GDB abstract data structure, you will get useless results. Instead, download and install one of following tools to properly view the contents of STL containers from within GDB. * GDB 7.0 will include support for writing pretty-printers in Python. This feature, combined with the pretty-printers in the libstdc++ svn repository, yields the best way to visualize C++ containers. Some distros (Fedora 11+) ship all this code in a way that requires no configuration; in other cases, this email message explains how to set everything up. The main points have been redacted here: Check-out the latest Python libstdc++ printers to a place on your machine. In a local directory, do: svn co svn://gcc.gnu.org/svn/gcc/trunk/libstdc++-v3/python Add the following to your ~/.gdbinit. The path needs to match where the python module above was checked-out. So if checked out to: /home/maude/gdb_printers/, the path would be as written in the example: python import sys sys.path.insert(0, '/home/maude/gdb_printers/python') from libstdcxx.v6.printers import register_libstdcxx_printers register_libstdcxx_printers (None) end The path should be the only element that needs to be adjusted in the example above. Once loaded, STL classes that the printers support should printed in a more human-readable format. To print the classes in the old style, use the /r (raw) switch in the print command (i.e., print /r foo). This will print the classes as if the Python pretty-printers were not loaded. * gdb-stl-views is a set of GDB macros that can display the contents of many STL containers: list, vector, map, multimap, set, multiset, dequeue, stack, queue, priority_queue, bitset, string, and widestring. Writen and currently maintained by Dan Marinescu - PhD. The author formally disclaims copyright to this source code. In place of a legal notice, here is a blessing: May you do good and not evil. May you find forgiveness for yourself and forgive others. May you share freely, never taking more than you give! * gdb++ is a Perl script which extends gdb. It comes bundled as part of the Devel::GDB::Reflect Perl module. First use CPAN to install the module, then follow the gdb++ usage instructions. Developed by Stanford PhD student Antal Novak. * There are other options. Tom Malnar wrote a set of GDB macros similar to Dan's ( http://thread.gmane.org/gmane.comp.gcc.g++.general/4060/focus=4167 ) but it doesn't cover as wide a variety of containers. Gilad Mishne wrote a different set of macros ( http://www.stanford.edu/~afn/gdb_stl_utils/ ) but it is long unmaintained and it works only with SGI's STL implementation, which very few GCC users use. * Iterators: how to display the item the iterator points at (tested on gdb 6 with a list): print *(iter._M_current)