#include <boost/iterator/filter_iterator.hpp>
#include <boost/iterator/transform_iterator.hpp>

//F = transformation function, P = predicate, C = container
template<typename F, typename P, typename C>
struct Comprehension
{
private:
	typedef boost::filter_iterator<P, typename C::iterator> FilterIter;
public:
	typedef boost::transform_iterator<F, FilterIter> ComprehensionIterator;

	Comprehension(const F& function, const P& predicate, const C& container):
		mContainer(container),
		mBegin(FilterIter(predicate, mContainer.begin(), mContainer.end()), function),
		mEnd(FilterIter(predicate, mContainer.end(), mContainer.end()), function)
	{
	}
	inline ComprehensionIterator begin(void){return mBegin;}
	inline ComprehensionIterator end(void){return mEnd;}
	
private:
	C mContainer;	
	ComprehensionIterator mBegin,mEnd;

};