Microsoft KB Archive/156742

= INFO: STL Sample for the replace_copy Function =

Article ID: 156742

Article Last Modified on 9/23/2003

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APPLIES TO

 The Standard C++ Library, when used with:  Microsoft Visual C++ 4.2 Enterprise Edition

 Microsoft Visual C++ 5.0 Enterprise Edition

 Microsoft Visual C++ 6.0 Enterprise Edition

 Microsoft Visual C++ 4.2 Professional Edition</li></ul>

 Microsoft Visual C++ 5.0 Professional Edition</li></ul>

 Microsoft Visual C++ 6.0 Professional Edition</li></ul>

 Microsoft Visual C++ 6.0 Standard Edition</li></ul>

 Microsoft Visual C++ .NET 2002 Standard Edition</li></ul>

 Microsoft Visual C++ .NET 2003 Standard Edition</li></ul> </li></ul>

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This article was previously published under Q156742

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SUMMARY
The sample code below illustrates how to use the replace_copy STL function in Visual C++.

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

Description
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.

Sample Code
NOTE: The first line in the sample code section says:

// Compile options needed: /GX

In VC++ .NET, /EHsc is set by default and is equivalent to /GX. ////////////////////////////////////////////////////////////////////// // // Compile options needed: /GX // // replace_copy.cpp : 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. // // Written by Kalindi Sanghrajka // of Microsoft Product Support Services, // Software Core Developer Support. // Copyright (c) 1996 Microsoft Corporation. All rights reserved. //////////////////////////////////////////////////////////////////////

// disable warning C4786: symbol greater than 255 character, // okay to ignore


 * 1) pragma warning(disable: 4786)

// disable warning C4244: possible loss of data, // okay to ignore


 * 1) pragma warning(disable: 4244)


 * 1) include
 * 2) include
 * 3) include
 * 4) include

using namespace std; // std c++ libs implemented in std #endif
 * 1) if _MSC_VER > 1020  // if VC++ version is > 4.2

void main

{

const int MAX_ELEMENTS = 8 ;

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

} Program Output is: <pre class="fixed_text">Numbers { 10 20 10 15 12 7 9 10 } <BR/><BR/> Total number of elements copied to Result = 8 Result { 30 20 30 15 12 7 9 30  }

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