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#pragma once
#include "local-coords.hpp"
#include <iterator>
#include <utility>
#include <type_traits>
namespace Magnum::Examples {
struct tile;
template<typename T> class basic_tile_iterator;
template<typename T> struct tile_tuple;
} // namespace Magnum::Examples
namespace std {
template<typename T> struct tuple_size<Magnum::Examples::tile_tuple<T>> : std::integral_constant<std::size_t, 3> {};
template<> struct tuple_element<0, Magnum::Examples::tile_tuple<Magnum::Examples::tile>> { using type = Magnum::Examples::tile&; };
template<> struct tuple_element<0, Magnum::Examples::tile_tuple<const Magnum::Examples::tile>> { using type = const Magnum::Examples::tile&; };
template<> struct tuple_element<0, const Magnum::Examples::tile_tuple<Magnum::Examples::tile>> { using type = const Magnum::Examples::tile&; };
template<typename T> struct tuple_element<1, Magnum::Examples::tile_tuple<T>> { using type = std::size_t; };
template<typename T> struct tuple_element<2, Magnum::Examples::tile_tuple<T>> { using type = Magnum::Examples::local_coords; };
} // namespace std
namespace Magnum::Examples {
template<typename T>
struct tile_tuple {
tile_tuple(T* ptr, std::size_t pos) : data{ptr, pos} {}
tile_tuple(const tile_tuple<T>&) = default;
tile_tuple<T>& operator=(const tile_tuple<T>&) = default;
template <std::size_t N>
typename std::tuple_element<N, tile_tuple<T>>::type get()
{
auto& [ptr, pos] = data;
if constexpr(N == 0)
return ptr[pos];
else if constexpr(N == 1)
return pos;
else if constexpr(N == 2)
return local_coords{pos};
else
return std::void_t<std::integral_constant<int, N>>();
}
template <std::size_t N>
typename std::tuple_element<N, const tile_tuple<const T>>::type get() const {
return const_cast<tile_tuple<T>&>(*this).get<N>();
}
auto operator<=>(const tile_tuple<T>&) const noexcept = default;
protected:
std::tuple<T*, std::size_t> data = {nullptr, 0};
};
} // namespace Magnum::Examples
namespace Magnum::Examples {
template<typename T>
class basic_tile_iterator final : private tile_tuple<T> {
public:
explicit basic_tile_iterator(T* ptr, std::size_t pos) noexcept : tile_tuple<T>{ptr, pos} {}
basic_tile_iterator(const basic_tile_iterator&) = default;
basic_tile_iterator<T>& operator=(const basic_tile_iterator<T>&) = default;
auto operator<=>(const basic_tile_iterator<T>&) const noexcept = default;
void swap(basic_tile_iterator<T>& other) { std::swap(this->data, other.data); }
basic_tile_iterator<T>& operator++() { auto& [ptr, pos] = this->data; pos++; return *this; }
basic_tile_iterator<T> operator++(int) { auto tmp = *this; operator++(); return tmp; }
tile_tuple<T>* operator->() { return this; }
tile_tuple<T>& operator*() { return *this; }
};
extern template class basic_tile_iterator<tile>;
extern template class basic_tile_iterator<const tile>;
} // namespace Magnum::Examples
namespace std {
template<typename Tile>
class iterator_traits<Magnum::Examples::basic_tile_iterator<Tile>> {
using T = Magnum::Examples::basic_tile_iterator<Tile>;
public:
using difference_type = std::ptrdiff_t;
using value_type = T;
using reference = T&;
using pointer = T*;
using iterator_category = std::input_iterator_tag; //usually std::forward_iterator_tag or similar
};
} // namespace std
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