#pragma once
#include <vector>
using namespace std;
template<class It>
class IteratorRange {
public:
IteratorRange(It b, It e) : begin_(b), end_(e), size_(std::distance(b, e)) {}
It begin() const {
return begin_;
}
It end() const {
return end_;
}
size_t size() const {
return size_;
}
private:
It begin_, end_;
size_t size_;
};
template <typename It>
class Slicer {
public:
Slicer(It begin_it, It end_it, size_t page_size) {
while (begin_it != end_it) {
size_t slice_size = std::min(page_size, static_cast<size_t>(distance(begin_it, end_it)));
pages_.push_back(IteratorRange<It>(begin_it, begin_it + slice_size));
begin_it += slice_size;
}
}
auto begin() {
return pages_.begin();
}
auto begin() const {
return pages_.begin();
}
auto end() {
return pages_.end();
}
auto end() const {
return pages_.end();
}
size_t size() const {
return pages_.size();
}
private:
std::vector<IteratorRange<It>> pages_;
};
template <typename C>
auto Slice(C& c, size_t page_size) {
return Slicer(c.begin(), c.end(), page_size);
}