(C++) std::remove_copy_if

 

Algorithm that IMHO could have better be called std::copy_if_not, as it does not remove anything, and only copies the elements that do not fulfull the predicate.

 

Prefer algorithm calls over hand-written loops [1,2].

 

 

 

 

 

Example

 

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#include <algorithm> #include <iostream> #include <iterator> #include <list> struct IsEven : public std::unary_function<bool,int> {   const bool operator()(const int i) { return i % 2 == 0 ; } }; int main() {   std::list<int> v;   for (int i=0; i!=10; ++i) v.push_back(i);   std::list<int> temp;   std::remove_copy_if(v.begin(),v.end(), std::back_inserter(temp), IsEven() );   std::cout << "Content of v:" << std::endl;   std::copy(v.begin(), v.end(), std::ostream_iterator<int>(std::cout," "));   std::cout << "Content of temp:" << std::endl;   std::copy(temp.begin(), temp.end(), std::ostream_iterator<int>(std::cout," ")); }

 

 

 

 

 

Screen output

 

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Content of v: 0 1 2 3 4 5 6 7 8 9 Content of temp: 1 3 5 7 9

 

 

 

 

 

External links

 

• SGI's std:: remove_copy_if page
• C++ Reference's std::remove_copy_if page

 

 

 

 

 

References

 

1. Bjarne Stroustrup. The C++ Programming Language (3rd edition). ISBN: 0-201-88954-4. Chapter 18.12.1: 'Prefer algorithms to loops.'
2. Scott Meyers. Effective STL. ISBN: 0-201-74962-9. Item 43: 'Prefer algorithm calls over hand-written loops'