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remove_copy_if


Category: algorithms	Component type: function

Prototype

template <class InputIterator, class OutputIterator, class Predicate>
OutputIterator remove_copy_if(InputIterator first, InputIterator last,
                              OutputIterator result, Predicate pred);

Description

Remove_copy_if copies elements from the range [first, last) to a range beginning at result, except that elements for which pred is true are not copied. The return value is the end of the resulting range. This operation is stable, meaning that the relative order of the elements that are copied is the same as in the range [first, last).

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.
InputIterator's value type is convertible to a type in OutputIterator's set of value types.
Predicate is a model of Predicate.
InputIterator's value type is convertible to Predicate's argument type.

Preconditions

[first, last) is a valid range.
There is enough space in the output range to store the copied values. That is, if there are n elements in [first, last) that do not satisfy pred, then [result, result+n) is a valid range.
result is not an iterator in the range [first, last).

Complexity

Linear. Exactly last - first applications of pred, and at most last - first assignments.

Example

Fill a vector with the nonnegative elements of another vector.

vector<int> V1;
V.push_back(-2);
V.push_back(0);
V.push_back(-1);
V.push_back(0);
V.push_back(1);
V.push_back(2);

vector<int> V2;
remove_copy_if(V1.begin(), V1.end(), 
               back_inserter(V2),
               bind2nd(less<int>(), 0));