C++ - Iterating over std::vector<> returned from find_if

c++, iterator, vector

Solution

// find_if example
#include <iostream>     // std::cout
#include <algorithm>    // std::find_if
#include <vector>       // std::vector

bool IsOdd (int i) {
  return ((i%2)==1);
}

int main () {
  std::vector<int> myvector;

  myvector.push_back(10);
  myvector.push_back(25);
  myvector.push_back(40);
  myvector.push_back(55);


  std::vector<int>::iterator it = std::find_if (myvector.begin(), myvector.end(), IsOdd); 
  std::cout << "ODD values are: " << std::endl;     

  while(it != myvector.end() ){

    std::cout << *it  << " in position " << (it - myvector.begin())  << '\n';
    it = std::find_if (++it, myvector.end(), IsOdd); 
  }
  return 0;
}

EDIT: Changed `it+1` to `++it` see @David Rodríguez - dribeas comment below.

Problem

I'm learning C++, so I feel like this should be a very simple answer - but I can't seem to find it. So I apologize in advance if it's naive. I have a `std::vector<int>` of of values, and I am trying to find the indices of the odd values. I am following the code from here: (repeated below): ``` // find_if example #include <iostream> // std::cout #include <algorithm> // std::find_if #include <vector> // std::vector bool IsOdd (int i) { return ((i%2)==1); } int main () { std::vector<int> myvector; myvector.push_back(10); myvector.push_back(25); myvector.push_back(40); myvector.push_back(55); std::vector<int>::iterator it = std::find_if (myvector.begin(), myvector.end(), IsOdd); std::cout << "The first odd value is " << *it << '\n'; return 0; } ``` This example prints the first odd value. How could I extend this to give me the index values for each of the odd values in `myvector`? Is this the correct approach?

Original source