bloom_filter.h

#ifndef BLOOM_FILTER_H
#define BLOOM_FILTER_H

#include <string>

namespace bf {

template <typename Derived>
class bloom_filter
{
public:
    template <typename T>
    void add(const T& x)
    {
        ++n_;
        derived().add(x);
    }

    template <typename T>
    void remove(const T& x)
    {
        --n_;
        derived().remove(x);
    }

    template <typename T>
    unsigned count(const T& x) const
    {
        return derived().count(x);
    }

    void clear()
    {
        n_ = 0;
        derived().clear();
    }

    unsigned long n() const
    {
        return n_;
    }

    std::string to_string() const
    {
        return derived().to_string();
    }

protected:
    bloom_filter()
    {
    };

private:
    //
    // CRTP interface
    //
    template <typename D>
    D& derived() const
    {
        return *static_cast<D*>(this);
    }

    template <typename D>
    const D& derived() const
    {
        return *static_cast<const D*>(this);
    }

protected:
    unsigned long n_;
};

} // namespace bf

#endif