Question

I have the following code:

using namespace std;
vector<string*> v;
{
  string s = "hello";
  v.push_back(&s);
}
{
  string ss = "goodbye";
  v.push_back(&ss);
}

cout << v.at(0)->c_str() << endl;
cout << v.at(1)->c_str() << endl;

which prints

goodbye
goodbye

if I remove the scope parenthesis the code will print

hello
goodbye

What exactly happens when I leave the first scope, that the pointer to the first string now points to the second one?

Answer 1

The stored pointers become dangling pointers after the scope and any attempt to read what they point to yields undefined behavior.