Known STL bug?

[Shakti]

Just wanted to know if the following program has a known STL bug. The program crashes with both VS 6, VS.Net 2002 and MingW Developer Studio. Here is the program:

#include <vector>

int main(int argc, char **argv) 
{
	std::vector<int> vec;
	vec.push_back(10);
	//vec.push_back(20);
	std::vector<int>::iterator iter;
	for(iter=vec.begin(); iter!=vec.end();iter++)
		iter = vec.erase(iter);
}

If you uncomment the second push_back it works fine though.

[anonytmouse]

	for(iter=vec.begin(); iter!=vec.end();iter++)
		iter = vec.erase(iter);

is equivalent to:

iter = vec.begin();
while (iter != vec.end())
{
    iter = vec.erase(iter);
    iter++;
}

Let's see what happens with one item in the vector:

iter = vec.begin();
while (iter != vec.end())
{
    iter = vec.erase(iter); /* Returns vec.end() */
    iter++; /* Moves to vec.end() + 1 */

    /* Loop will not stop as we are at vec.end() + 1, therefore we will crash. */
}

and with two items:

iter = vec.begin();
while (iter != vec.end())
{
    iter = vec.erase(iter); /* Returns vec.end() - 1 (second item in vec) */
    iter++; /* Moves to vec.end() */

    /* Loop will stop as we are at vec.end(), but not every item will be deleted. */
}

In fact, the code will crash with if vec has an odd number of items and not crash if vec has an even number of items.

[Shakti]

ah! that makes sense, thanks for clearing this up.