Program received signal SIGSEGV, Segmentation fault.
0x08049bb4 in std::_Rb_tree<int, std::pair<int const, Dier*>, std::_Select1st<std::pair<int const, Dier*> >, std::less<int>, std::allocator<std::pair<int const, Dier*> > >::_M_begin (this=0x0) at /usr/lib/gcc/i386-redhat-linux/4.0.1/../../../../include/c++/4.0.1/bits/stl_tree.h:462
462           { return static_cast<_Link_type>(this->_M_impl._M_header._M_parent); }
Current language:  auto; currently c++
(gdb) up
#1  0x08049cad in std::_Rb_tree<int, std::pair<int const, Dier*>, std::_Select1st<std::pair<int const, Dier*> >, std::less<int>, std::allocator<std::pair<int const, Dier*> > >::lower_bound (this=0x0, __k=@0x8ae21d4) at /usr/lib/gcc/i386-redhat-linux/4.0.1/../../../../include/c++/4.0.1/bits/stl_tree.h:1184
1184          _Link_type __x = _M_begin(); // Current node.
(gdb) up
#2  0x08049d55 in std::map<int, Dier*, std::less<int>, std::allocator<std::pair<int const, Dier*> > >::lower_bound (this=0x0, __x=@0x8ae21d4)
    at /usr/lib/gcc/i386-redhat-linux/4.0.1/../../../../include/c++/4.0.1/bits/stl_map.h:540
540           { return _M_t.lower_bound(__x); }
(gdb) bt
#0  0x08049bb4 in std::_Rb_tree<int, std::pair<int const, Dier*>, std::_Select1st<std::pair<int const, Dier*> >, std::less<int>, std::allocator<std::pair<int const, Dier*> > >::_M_begin (this=0x0) at /usr/lib/gcc/i386-redhat-linux/4.0.1/../../../../include/c++/4.0.1/bits/stl_tree.h:462
#1  0x08049cad in std::_Rb_tree<int, std::pair<int const, Dier*>, std::_Select1st<std::pair<int const, Dier*> >, std::less<int>, std::allocator<std::pair<int const, Dier*> > >::lower_bound (this=0x0, __k=@0x8ae21d4) at /usr/lib/gcc/i386-redhat-linux/4.0.1/../../../../include/c++/4.0.1/bits/stl_tree.h:1184
#2  0x08049d55 in std::map<int, Dier*, std::less<int>, std::allocator<std::pair<int const, Dier*> > >::lower_bound (this=0x0, __x=@0x8ae21d4)
    at /usr/lib/gcc/i386-redhat-linux/4.0.1/../../../../include/c++/4.0.1/bits/stl_map.h:540
#3  0x0804ae0d in std::map<int, Dier*, std::less<int>, std::allocator<std::pair<int const, Dier*> > >::operator[] (this=0x0, __k=@0x8ae21d4)
    at /usr/lib/gcc/i386-redhat-linux/4.0.1/../../../../include/c++/4.0.1/bits/stl_map.h:336
#4  0x08049856 in Dierentuin::dierToevoegen (this=0x8ae21c0) at Dierentuin.cc:40
#5  0x0804927c in main ()
(gdb)