replace_copy_if
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replace_copy_if

Examines each element in a source range and replaces it if it satisfies a specified predicate while copying the result into a new destination range.

template<class InputIterator, class OutputIterator, class Predicate, class Type>
   OutputIterator replace_copy_if(
      InputIterator _First, 
      InputIterator _Last, 
      OutputIterator _Result, 
      Predicate _Pred, 
      const Type& _Val
   );

Parameters

_First
An input iterator pointing to the position of the first element in the range from which elements are being replaced.
_Last
An input iterator pointing to the position one past the final element in the range from which elements are being replaced.
_Result
An output iterator pointing to the position of the first element in the destination range to which elements are being copied.
_Pred
The unary predicate that must be satisfied is the value of an element is to be replaced.
_Val
The new value being assigned to the elements whose old value satisfies the predicate.

Remarks

The source and destination ranges referenced must not overlap and must both be valid: all pointers must be dereferenceable and within the sequences the last position is reachable from the first by incrementation.

The order of the elements not replaced remains stable.

The operator== used to determine the equality between elements must impose an equivalence relation between its operands.

The complexity is linear; there are (_Last – _First) comparisons for equality and at most (_Last – _First) assignments of new values.

Example

// alg_replace_copy_if.cpp
// compile with: /EHsc
#include <vector>
#include <list>
#include <algorithm>
#include <iostream>

bool greater6 ( int value )
{
   return value >6;
}

int main( ) {
   using namespace std;
   vector <int> v1;
   list <int> L1 (13);
   vector <int>::iterator Iter1;
   list <int>::iterator L_Iter1;

   int i;
   for ( i = 0 ; i <= 9 ; i++ )
   {
      v1.push_back( i );
   }

   int ii;
   for ( ii = 0 ; ii <= 3 ; ii++ )
   {
      v1.push_back( 7 );
   }

   random_shuffle ( v1.begin( ), v1.end( ) );

   int iii;
   for ( iii = 0 ; iii <= 13 ; iii++ )
   {
      v1.push_back( 1 );
   }

   cout << "The original vector v1 is:\n ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")." << endl;

   // Replace elements with a value of 7 in the 1st half of a vector
   // with a value of 70 and copy it into the 2nd half of the vector
   replace_copy_if ( v1.begin( ), v1.begin( ) + 14,v1.end( ) -14,
      greater6 , 70);

   cout << "The vector v1 with values of 70 replacing those greater"
        << "\n than 6 in the 1st half & copied into the 2nd half is:\n ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")." << endl;

   // Replace elements in a vector with a value of 70
   // with a value of 1 and copy into a list
   replace_copy_if ( v1.begin( ), v1.begin( ) + 13,L1.begin( ),
      greater6 , -1 );

   cout << "A list copy of vector v1 with the value -1\n replacing "
        << "those greater than 6 is:\n ( " ;
   for ( L_Iter1 = L1.begin( ) ; L_Iter1 != L1.end( ) ; L_Iter1++ )
      cout << *L_Iter1 << " ";
   cout << ")." << endl;
}

Output

The original vector v1 is:
 ( 7 1 9 2 0 7 7 3 4 6 8 5 7 7 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ).
The vector v1 with values of 70 replacing those greater
 than 6 in the 1st half & copied into the 2nd half is:
 ( 7 1 9 2 0 7 7 3 4 6 8 5 7 7 70 1 70 2 0 70 70 3 4 6 70 5 70 70 ).
A list copy of vector v1 with the value -1
 replacing those greater than 6 is:
 ( -1 1 -1 2 0 -1 -1 3 4 6 -1 5 -1 ).

See Also

<algorithm> Members | replace_copy_if Sample

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