Re: Memory footprint of std::vector<std::vector<T> >

On Dec 10, 3:24 pm, Rune Allnor <all...@tele.ntnu.no> wrote:


Starting from VS2005, Microsoft has introduced a new feature called
"checked iterators" that affect several STL classes.
As a consequence, every time you access an element of std::vector<T>,
the vector bounds are checked.
The situation is even worse for std::vector<std::vector<T> > because
double checks are performed (I think it requires 4 comparison for
every element access).

In order to disable this "feature", you should set the symbol
_SECURE_SCL to 0 before including the stl headers.
This is an example taken from MSDN:

// checked_iterators_4.cpp
// compile with: /EHsc
#define _SECURE_SCL 0
#include <vector>
#include <iostream>
using namespace std;
int main() {
   vector<int> v;
   v.push_back(67);
   int i = v[0];
   cout << i << endl;
};

Apart from this, I suggest you to turn on all the optimizations (in
particular SSE2, it can make a big difference).

Regards,
The Librarian