replace_if (STL Samples)

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

template<class ForwardIterator, class Predicate, class Type> inline 
   void replace_if( 
      ForwardIterator First, 
      ForwardIterator Last, 
      Predicate Pred, 
      const Type& Value 
   )

Remarks

Note

The class/parameter names in the prototype do not match the version in the header file. Some have been modified to improve readability.

The replace_if algorithm replaces all elements from the range [First, Last) that cause the predicate to return true with Value.

Example

// replace_if.cpp
// compile with: /EHsc
// Illustrates how to use the replace_if function.
//
// Functions:
//    replace_if - Replace all elements from the sequence that
//                 satisfies a predicate with a specified 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 VECTOR_SIZE = 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 ;

    IntVector Numbers(VECTOR_SIZE) ;   //vector containing numbers

    IntVectorIt start, end, it ;

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

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

    //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 ;

    cout << "Before calling replace_if" << endl ;

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

    // replace all elements from Numbers that are <= 10 with 4
     replace_if(start, end, bind2nd(less_equal<int>(), 10), 4 ) ;

    cout << "After calling replace_if" << endl ;

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

}

Output

Before calling replace_if
Numbers { 10 20 10 15 12 7 9 10  }

After calling replace_if
Numbers { 4 20 4 15 12 4 4 4  }

Requirements

Header: <algorithm>

See Also

Concepts

Standard Template Library Samples