Why there is no std::copy_if algorithm?

Question

Is there any specific reason for not having std::copy_if algorithm in C++ ? I know I can use std::remove_copy_if to achieve the required behavior. I think it is coming in C+

Answer 1

Just for completeness I will add that boost has boost::algorithm::copy_if for those of you who cannot use c++11's version (like me) in boost/algorithm/cxx11/copy_if.hpp which will use std::copy_if when:

#if __cplusplus >= 201103L
//  Use the C++11 versions of copy_if if it is available
using std::copy_if;         // Section 25.3.1
#else

Example:

#include 
#include  // for 'list_of()'
#include 

#include 
#include 
#include 

struct Odd
{
  bool operator()(int n)
  {
    return n & 1;
  }
};

int main()
{
  std::vector v = boost::assign::list_of(0)(1)(2)(3)(4);
  BOOST_FOREACH(int i, v)
    std::cout << i << ' ' ;

  std::vector out;
  boost::algorithm::copy_if(v.begin(), v.end(), std::back_inserter(out), Odd());

  std::cout << std::endl;

  BOOST_FOREACH(int i, out)
    std::cout << i << ' ' ;

}

Output:

0 1 2 3 4 
1 3