remove_copy (STL Samples)
Illustrates how to use the remove_copy Standard Template Library (STL) function in Visual C++.
template<class ForwardIterator, class OutputIterator, class Type> inline
OutputIterator remove_copy(
ForwardIterator First,
ForwardIterator Last,
OutputIterator Result,
const T& Value
)
Remarks
备注
The class/parameter names in the prototype do not match the version in the header file. Some have been modified to improve readability.
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.
Example
// remove_copy.cpp
// compile with: /EHsc
// 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.
//////////////////////////////////////////////////////////////////////
// disable warning C4786: symbol greater than 255 character,
// 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
// 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 ;
}
Output
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 }
Requirements
Header: <algorithm>