Re: Am I misusing std::vector?

Hi,

I was surprised by the output of the program below. From what I
understand from the C++ STL documentation, vector<T>::resize(N), will
create N *newly constructed* objects of T. So, I expected *v[0].ip to
be equal to 0, and *v[sz-1].ip equal to -77. However, I discovered,
using a few different compilers (two different versions of gcc, and
icc), that both return -77. It turns out that only *one* object is
being constructed and this one object seems to be bitwise copied to the
other members. See my code below and try it for yourself.
Am I missing something here?

Regards,

Marcel Loose.

<code>
#include <vector>
#include <iostream>
using namespace std;

struct A
{
 A(int i = 0) { ip = new int(i); }
 ~A() { delete ip; }
 int* ip;
};

int main()
{
 const unsigned sz = 1000000;
 vector<A> v;
 v.resize(sz);
 *v[sz-1].ip = -77;
 cout << "v.size() = " << v.size() << endl;
 cout << "v[0].ip = " << v[0].ip << "; " << "*v[0].ip = " <<
*v[0].ip << endl;
 cout << "v[sz-1].ip = " << v[sz-1].ip << "; " << "*v[sz-1].ip = "
<< *v[sz-1].ip << endl;
 return 0;
}
</code>