Use of the replace_copy() in C++

[D-Mon]

Hi, How are you Everyone. I am the student of the MscIT. I have to submit the Project on the functions of the C++ language in three days. I can have the well knowledge of the functions that can be used in the C++ language. Even if, I can not know much more about the replace_copy() function of the C++ language. So, I want to know about the replace_copy() function of the C++ language. I also want to know How the replace_copy() function can be used in the C++ Programs. Reply Me!!

[Praetor]

The replace_copy() function can be used in the C++ language to Copy range replacing value. The following can be the general syntax of the replace_copy() function :

template < class IptItrtr, class OtptItrtr, class T >
  OtptItrtr replace_copy ( IptItrtr first, IptItrtr last,
                                OtptItrtr result,
                                const T& old_value, const T& new_value );

[Katty]

I suggest you to carefully go through the following code of lines that can be helpful for you to get the information or knowledge of the replace_copy() function in the C++ language :

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main ()
 {
  int mint[] = { 10, 20, 30, 30, 20, 10, 10, 20 };
  vector<int> myvctr (8);
  replace_copy (mint, mint+8, myvctr.begin(), 20, 99);
  cout << "myvctr contains:";
  for (vector<int>::iterator it=myvctr.begin(); it!=myvctr.end(); ++it)
    cout << " " << *it;
  cout << endl;
  return 0;
}

Output:

myvctr contains: 10 99 30 30 99 10 10 99

[kelfro]

The following can be the parameters of the replace_copy() function in the C++ language :
1. result : This parameter of the replace_copy() function can be used for Output iterator to the starting position of the range where the function's results can be stored. The range can includes as many an elements as [fst,lst).
2. new_value : This parameter of the replace_copy() function can has the replacement value.
3. fst, lst : These parameters of the replace_copy() function can be used for Input iterators to the final and starting positions in a given sequence. The range used can be as [first,last)
4. old_value : This parameter of the replace_copy() function can has the Value that can be replaced.

[Zecho]

Program :

#include <iostream>
#include <fstream>
#include <iterator>
#include <algorithm>
using namespace std;
int main(int arg, char *ag[])
{
  if(arg != 5) 
{
    cout << "Usage: replace in out oldchar newchar\n";
    return 1;
  }
  ifstream in(ag[1]);
  ofstream out(ag[2]);
  if(!in.isopen()) 
{
    cout << "Cannot open input file.\n";
    return 1;
  }
  if(!out.isopen()) 
{
    cout << "Cannot open output file.\n";
    return 1;
  }
  istreambufiterator<char> in_itr(in);
  ostreambufiterator<char> out_itr(out);
  replace_copy(in_itr, istreambuf_iterator<char>(),out_itr, *ag[3], *ag[4]);
  in.close();
  out.close();
  return 0;
}