Microsoft KB Archive/156533

= How to use the remove_copy STL function in Visual C++ =

Article ID: 156533

Article Last Modified on 7/15/2005

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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 Q156533

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SUMMARY
The sample code below illustrates how to use the remove_copy, begin, and end STL functions in Visual C++.

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Prototype
template<class ForwardIterator, class OutputIterator, class Type> inline OutputIterator remove_copy(ForwardIterator first,

ForwardIterator last, OutputIterator result, const T& 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 remove_copy algorithm copies all elements from the range (first, last) to the range starting at result, skipping any element that matches value. It returns an iterator positioned immediately after the last new element.

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 // // remove_copy.cpp : Illustrates how to use the remove_copy function. // // Functions: // //  remove_copy - copy the elements of a sequence to another sequence //                eliminating any elements that match value. //  begin - Returns an iterator that points to the first element in a //           sequence. //  end - Returns an iterator that points one past the end of a sequence. // // 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 // skipping any item that equals 10 last = remove_copy(start, end, resultIt, 10) ;

//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 }

Total number of elements copied to Result = 5 Result { 20 15 12 7 9 0 0 0 }

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