protected:

T iter_;

public:

IterBase(const T& iter)

: iter_(iter) {}

TDerived& operator++() {

++iter_;

return static_cast<TDerived&>(*this);

}

bool operator==(const TDerived& other) const {

return iter_ == other.iter_;

}

bool operator!=(const TDerived& other) const {

return iter_ != other.iter_;

}

TIter begin_;

TIter end_;

public:

Range(const TIter& begin, const TIter& end)

: begin_(begin)

, end_(end) {}

TIter begin() const {

return begin_;

}

TIter end() const {

return end_;

}