replace_copy (STL Samples)

Illustrates how to use the replace_copy Standard Template Library (STL) function in Visual C++.

template<class ForwardIterator, class OutputIterator, class Type> inline 
   OutputIterator replace_copy( 
      ForwardIterator First, 
      ForwardIterator Last, 
      OutputIterator Result, 
      const T& Old_Value, 
      const T& New_Value 
   )

Remarks

The replace_copy algorithm copies all elements from the range [First, Last) to a same-size range starting at result, replacing all occurrences of Old_Value with New_Value in the resulting sequence. It returns an iterator positioned immediately after the last new element in the resulting sequence.

Example

// replace_copy.cpp
// compile with: /EHsc
// Illustrates how to use the replace_copy function.
//
// Functions:
//    replace_copy - Copy the elements of a sequence to another
//                   same-size sequence replacing any elements
//                   that match a value with another value.

// disable warning C4786: symbol greater than 255 characters,
// okay to ignore
#pragma warning(disable: 4786)

#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>

using namespace std;


int main()
{
    const int MAX_ELEMENTS = 8 ;

    // Define a template class vector of integers
    typedef vector<int > IntVector ;

    //Define an iterator for template class vector of integer
    typedef IntVector::iterator IntVectorIt ;

    //vector containing numbers
    IntVector Numbers(MAX_ELEMENTS), Result(MAX_ELEMENTS) ;

    IntVectorIt start, end, it, last, resultIt ;

    //Initialize vector Numbers
    Numbers[0] = 10 ;
    Numbers[1] = 20 ;
    Numbers[2] = 10 ;
    Numbers[3] = 15 ;
    Numbers[4] = 12 ;
    Numbers[5] = 7 ;
    Numbers[6] = 9 ;
    Numbers[7] = 10 ;

    start = Numbers.begin() ;   // location of first
                                // element of Numbers

    end = Numbers.end() ;       // one past the location
                                // last element of Numbers

    resultIt = Result.begin() ; // location of first
                                // element of Result

    // print content of Numbers
    cout << "Numbers { " ;
    for(it = start; it != end; it+)
        cout << *it << " " ;
    cout << " }\n" << endl ;

    // copy all elements from Numbers to Result
    // replacing any item that equals 10 with 30
    last = replace_copy(start, end, resultIt, 10, 30) ;

    //print number of elements copied to Result
    cout << "Total number of elements copied to Result = "
        << last - resultIt << endl ;

    start = Result.begin() ;   // location of first
                                // element of Result

    end = Result.end() ;       // one past the location
                               // last element of Result

    // print content of Result
    cout << "Result  { " ;
    for(it = start; it != end; it+)
        cout << *it << " " ;
    cout << " }\n" << endl ;

}

Output

Numbers { 10 20 10 15 12 7 9 10  }

Total number of elements copied to Result = 8
Result  { 30 20 30 15 12 7 9 30  }

Requirements

Header: <algorithm>

See Also

Concepts

Standard Template Library Samples