[Mingw-users] Problem using std::list

[Rick X. <li...@xw...>]

Hi,

This may be OT but perhaps someone can tell me what's wrong with this code
that exhibits odd behaviour from std::list, where a list is accessed through
another list.

Using: Mingw 2.0.0.3 (gcc 3.2) on win98
Command line: g++ -Wall minimal.cpp -o minimal.exe

------------------------------------------

#include <iostream>
#include <list>
using std::list;
using std::cout;
using std::endl;


// the class we are inserting to
class A
{
public:
 A ()
 {
  it = alist.begin();
  Insert (10);
  cout << "start size: " << alist.size() << endl;
 }
 void Insert (int i)
 {
  it = alist.insert (it, i);
  cout << "insert, size now: " << alist.size() << endl;
 }
 void PushBack (int i)
 {
  alist.push_back (i);
  cout << "pushback, size now: " << alist.size() << endl;
 }
 list<int> alist;
 list<int>::iterator it;
};

// this class has a list of a class containing a list
class B
{
public:
 B ()
 {
  it = blist.begin();
 }
 void Insert ()
 {
  A a;
  it = blist.insert (it, a);
 }

 list<A> blist;
 list<A>::iterator it;
};


int main()
{
 // do lists
 B b;
 b.Insert ();

 b.it->Insert(100);
 b.it->PushBack(200);

    return 0;
}

----------------------------------------

I get this output:

>minimal
insert, size now: 1
start size: 1
insert, size now: 1
pushback, size now: 2
>Exit code: 0

----------------------------------
The initial Insert() in the constructor of A works fine. However, the
subsequent Insert() does not increment the list size, while the PushBack()
does.

Any insight appreciated,
Rick