Untitled

Alternative for std:vector to remove its elements while going through a loop?
for(unsigned int j = 0; j < rectArray.size(); j++)
{
 if( rectArray[j] == 2 )
  {
   rectArray.erase(rectArray.begin() + j);
  }
//...
}

for (auto it = rectArray.begin(); it != rectArray.end(); ++it)
{
    // Access the current element with *it
    // If you want you can pass `it` and `rectArray.end()` as
    // the lower and upper bounds of the new collection,
    // rather than doing expensive resizes of the vector.
}

for (auto it : rectArray) {
   // same as before
}

auto end = std::end(rectArray);
for(auto it = std::begin(rectArray); it != end; ++it)
{
    if(it->remove_me()))
        std::swap(*it, *--end); // or even faster *it = std::move(*--end);
}
rectArray.erase(end, std::end(rectArray));

#include <vector>
#include <list>
#include <algorithm>

using namespace std;

class Widget
{
public:
   explicit Widget(int someNumber);
   bool ShouldDelete();
   bool ShouldDeleteComplex(int a, int b, int c);
private:
   int _someNumber;
};

Widget::Widget(int someNumber) : _someNumber(someNumber)
{
}

bool Widget::ShouldDelete()
{
   if (_someNumber > 2)
   {
      return true;
   }
   return false;
}

bool Widget::ShouldDeleteComplex(int a, int b, int c)
{
   if ((a * b - c) > _someNumber)
   {
      return true;
   }
   return false;
}

int main()
{
   list<Widget> lw;

   lw.push_back(Widget(1));
   lw.push_back(Widget(2));
   lw.push_back(Widget(3));

   // delete from list using functor
   lw.remove_if(mem_fun_ref(&Widget::ShouldDelete));

   // delete from list using lambda function
   lw.remove_if([] (Widget& x) { return x.ShouldDeleteComplex(1, 2, 0); }   );

   vector<Widget> vw;

   vw.push_back(Widget(1));
   vw.push_back(Widget(2));
   vw.push_back(Widget(3));

   // delete using functor
   vw.erase(remove_if(vw.begin(), vw.end(), mem_fun_ref(&Widget::ShouldDelete)), vw.end());

   // delete using lambda function
   vw.erase(
      remove_if(vw.begin(), vw.end(),
        [] (Widget& x) { return x.ShouldDeleteComplex(1, 2, 0); }
     ),
      vw.end());

   return 0;
}