 # replace_copy_if  Category: algorithms Component type: function

### Prototype

```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)
```

### Description

Replace_copy_if copies elements from the range [first, last) to the range [result, result + (last-first)), except that any element for which pred is true is not copied; new_value is copied instead. More precisely, for every integer n such that 0 <= n < last-first, replace_copy_if performs the assignment *(result+n) = new_value if pred(*(first+n)), and *(result+n) = *(first+n) otherwise.

### Definition

Defined in the standard header algorithm, and in the nonstandard backward-compatibility header algo.h.

### Requirements on types

• InputIterator is a model of Input Iterator.
• OutputIterator is a model of Output Iterator.
• Predicate is a model of Predicate.
• T is convertible to Predicate's argument type.
• T is Assignable.
• T is convertible to a type in OutputIterator's set of value types.

### Preconditions

• [first, last) is a valid range.
• There is enough space in the output range to store the copied values. That is, [result, result + (last-first)) is a valid range.
• result is not an iterator within the range [first, last).

### Complexity

Linear. Replace_copy performs exactly last - first applications of pred and exactly last - first assignments.

### Example

Copy elements from one vector to another, replacing all negative numbers with 0.
```vector<int> V1;
V1.push_back(1);
V1.push_back(-1);
V1.push_back(-5);
V1.push_back(2);

vector<int> V2(4);

replace_copy_if(V1.begin(), V1.end(), V2.begin(),
bind2nd(less<int>(), 0),
0);
assert(V == 1 && V == 0 && V == 0 && V == 2);
```

### Notes  