#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <vector>
using namespace std;
class Query;
class IFilter
{
public:
virtual void modifyQuery(Query* query) = 0;
};
template <typename T>
class Filter : public IFilter
{
public:
virtual void modifyQuery(Query* query);
};
class DateFilter;
class NameFilter;
class Query
{
public:
void applyFilter(IFilter* filter)
{
cout << "applying Filter" << endl;
filter->modifyQuery(this);
}
void applyFilter(NameFilter* filter)
{
cout << "applying NameFilter" << endl;
}
void applyFilter(DateFilter* filter)
{
cout << "applying DateFilter" << endl;
}
};
template <typename T>
void Filter<T>::modifyQuery(Query* query)
{
query->applyFilter(dynamic_cast<T*> (this));
}
class DateFilter : public Filter<DateFilter>
{
};
class NameFilter : public Filter<NameFilter>
{
};
int main()
{
Query* query = new Query();
IFilter* nameFilter = new NameFilter();
IFilter* dateFilter = new DateFilter();
std::vector<IFilter*> filterList;
filterList.push_back(nameFilter);
filterList.push_back(dateFilter);
for (int i = 0; i < 2; ++i)
{
query->applyFilter(filterList[i]);
}
return 0;
}