[Boost-users] remove_if and transform_iterator

13 Dec 2005

      Hi,

Can transform_iterator be used in conjunction with remove_if algorithm?
The compiler (vc7.1, vc8, g++) is refusing to compile this:

#include <string>
#include <utility>
#include <vector>
#include <functional>
#include <cassert>
#include <iostream>
#include <boost/iterator/transform_iterator.hpp>

std::vector<std::pair<std::string, int> > c;

struct to_num {
	typedef int result_type;

	int operator()(const std::pair<std::string, int>& p) const
	{
		return p.second;
	}
};

int main()
{
	using std::make_pair;

	c.push_back(make_pair("A", 2));
	c.push_back(make_pair("A", 3));
	c.push_back(make_pair("A", 4));

	c.push_back(make_pair("A", 15));
	c.push_back(make_pair("A", 16));
	c.push_back(make_pair("A", 17));
	assert(c.size() == 6);

	std::remove_if(
		boost::make_transform_iterator(c.begin(), to_num()),
		boost::make_transform_iterator(c.end(), to_num()),
		std::bind1st(std::less_equal<int>(), 10));

	assert(c.size() == 6);
}

Regards,
Josue

[Boost-users] remove_if and transform_iterator

Josue Gomes