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#pragma once
#include "local-coords.hpp"
#include "tile.hpp"
#include <iterator>
#include <tuple>
#include <utility>
#include <type_traits>
namespace Magnum::Examples {
template<typename T>
class basic_tile_iterator;
struct tile;
} // namespace Magnum::Examples
namespace std {
template<typename T>
constexpr void swap(Magnum::Examples::basic_tile_iterator<T>& lhs,
Magnum::Examples::basic_tile_iterator<T>& rhs) noexcept;
} // namespace std
namespace Magnum::Examples {
namespace detail {
template<typename T>
class tile_tuple_wrapper final {
using value_type = std::tuple<T&, std::size_t, local_coords>;
value_type value;
public:
constexpr tile_tuple_wrapper(value_type x) : value(x) {}
constexpr value_type& operator*() noexcept { return value; }
constexpr value_type* operator->() noexcept { return &value; }
};
} // namespace detail
template<typename T>
class basic_tile_iterator final {
T* ptr;
std::size_t pos = 0;
friend constexpr void swap(basic_tile_iterator<T>& lhs, basic_tile_iterator<T>& rhs) noexcept;
public:
using value_type = std::tuple<T&, std::size_t, local_coords>;
explicit constexpr basic_tile_iterator(T* ptr, std::size_t pos) noexcept : ptr(ptr), pos(pos) {}
constexpr ~basic_tile_iterator() noexcept = default;
constexpr basic_tile_iterator<T>& operator=(const basic_tile_iterator<T>&) noexcept = default;
constexpr basic_tile_iterator<T>& operator++() noexcept { pos++; return *this; }
constexpr basic_tile_iterator<T> operator++(int) noexcept { auto tmp = *this; operator++(); return tmp; }
constexpr value_type operator*() const noexcept { // NOLINT(bugprone-exception-escape)
ASSERT(pos < TILE_COUNT);
return {ptr[pos], pos, local_coords{pos}};
}
constexpr detail::tile_tuple_wrapper<T> operator->() const noexcept { // NOLINT(bugprone-exception-escape)
return {operator*()};
}
constexpr auto operator<=>(const basic_tile_iterator<T>&) const noexcept = default;
};
template<typename T>
constexpr void swap(basic_tile_iterator<T>& lhs, basic_tile_iterator<T>& rhs) noexcept
{
using std::swap;
swap(lhs.ptr, rhs.ptr);
swap(lhs.pos, rhs.ptr);
}
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 = typename Magnum::Examples::basic_tile_iterator<Tile>::value_type;
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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