replace_copy_if


function template
<algorithm>
template < class InputIterator, class OutputIterator, class Predicate, class T >
  OutputIterator replace_copy_if ( InputIterator first, InputIterator last,
                                   OutputIterator result, Predicate pred,
                                   const T& new_value );

Copy range replacing value

Copies the values of the elements in the range [first,last) to the range positions beginning at location pointed by result, replacing those where pred is true by new_value.

The behavior of this function template is equivalent to:
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template < class InputIterator, class OutputIterator, class Predicate, class T >
  OutputIterator replace_copy_if ( InputIterator first, InputIterator last,
                                   OutputIterator result, Predicate pred,
                                   const T& new_value )
{
  for (; first != last; ++first, ++result)
    *result = (pred(*first))? new_value: *first;
  return result;
}


Parameters

first, last
Input iterators to the initial and final positions in a sequence. The range used is [first,last), which contains all the elements between first and last, including the element pointed by first but not the element pointed by last.
result
Output iterator to the initial position of the range where function results are stored. The range includes as many elements as [first,last).
pred
Unary predicate taking an element in the range as argument, and returning a value indicating the falsehood (with false, or a zero value) or truth (true, or non-zero) of some condition applied to it. This can either be a pointer to a function or an object whose class overloads operator().
new_value
Replacement value.


Return value

An iterator pointing to the element that follows the last element written in the result sequence.

Example

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// replace_copy_if example
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

bool IsOdd (int i) { return ((i%2)==1); }

int main () {
  vector<int> first,second;
  vector<int>::iterator it;

  // set some values:
  for (int i=1; i<10; i++) first.push_back(i);          // 1 2 3 4 5 6 7 8 9

  second.resize(first.size());   // allocate space
  replace_copy_if (first.begin(), first.end(), second.begin(), IsOdd, 0);
                                                        // 0 2 0 4 0 6 0 8 0

  cout << "second contains:";
  for (it=second.begin(); it!=second.end(); ++it)
    cout << " " << *it;

  cout << endl;
 
  return 0;
}


Output:
second contains: 0 2 0 4 0 6 0 8 0


Complexity

Applies pred and assigns values as many times as the number of elements in the range [first,last).

See also

remove_copy_if Copy range removing values (function template)
replace Replace value in range (function template)
replace_copy Copy range replacing value (function template)
transform Apply function to range (function template)