Inserting a value into a vector at a designated position

[BrowserUk]

I have a vector (of ints); and I want to insert a new int at a specified position, n.

vector has an insert method, but requires an iterator to specify the position.

How can I obtain an iterator to the specified position without iterating from begin() for n places?

Thanks, Buk.

[helios]

vector.begin() + i gives an iterator positioned at index i of the vector.

[Thomas1965]

Just add n to begin().

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

int main ()
{
  vector<int> numbers = {1,2,3,4,5,6,7,8,9,10};
  cout << "Original vector : \n";
  copy (numbers.begin(), numbers.end(), ostream_iterator<int>(cout, " "));
  numbers.insert (numbers.begin () + 5, 99);
  cout << "\nAfter inserting 99 at position 5 : \n";
  copy (numbers.begin (), numbers.end (), ostream_iterator<int> (cout, " "));
  system ("pause");
  return 0;
}

[BrowserUk]

Perfect. Thanks guys.

(Is there some way I might have derived information that from the docs http://www.cplusplus.com/reference/vector/vector/begin/ ?)

[helios]

All random access iterators can be added with an integer to give another random access iterator into the same container.

http://www.cplusplus.com/reference/iterator/RandomAccessIterator/

[jlb]

Why did you look at the documentation for vector.begin() instead of vector.insert()? Your question did state that your question was about the vector.insert() function. The vector.insert() does show adding an int to begin().

http://www.cplusplus.com/reference/vector/vector/insert/

 it = myvector.begin();

  std::vector<int> anothervector (2,400);
  myvector.insert (it+2,anothervector.begin(),anothervector.end());