BLT/include/blt/meta/iterator.h

117 lines
4.0 KiB
C++

#pragma once
/*
* Copyright (C) 2024 Brett Terpstra
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef BLT_META_ITERATOR_H
#define BLT_META_ITERATOR_H
#include <type_traits>
#include <iterator>
namespace blt::meta
{
template<typename Category>
struct is_input_iterator_category
{
constexpr static bool value = std::is_same_v<Category, std::input_iterator_tag>;
};
template<typename Category>
struct is_forward_iterator_category
{
constexpr static bool value = std::is_same_v<Category, std::forward_iterator_tag>;
};
template<typename Category>
struct is_bidirectional_iterator_category
{
constexpr static bool value = std::is_same_v<Category, std::bidirectional_iterator_tag>;
};
template<typename Category>
struct is_random_access_iterator_category
{
constexpr static bool value = std::is_same_v<Category, std::random_access_iterator_tag>;
};
template<typename Iter>
inline constexpr bool is_input_iterator_category_v = is_input_iterator_category<Iter>::value;
template<typename Iter>
inline constexpr bool is_forward_iterator_category_v = is_forward_iterator_category<Iter>::value;
template<typename Iter>
inline constexpr bool is_bidirectional_iterator_category_v = is_bidirectional_iterator_category<Iter>::value;
template<typename Iter>
inline constexpr bool is_random_access_iterator_category_v = is_random_access_iterator_category<Iter>::value;
template<typename Iter>
inline constexpr bool is_bidirectional_or_better_category_v =
is_bidirectional_iterator_category_v<Iter> || is_random_access_iterator_category_v<Iter>;
// this is required! :/
template<typename Iter>
struct is_input_iterator
{
constexpr static bool value = is_input_iterator_category_v<typename std::iterator_traits<Iter>::iterator_category>;
};
template<typename Iter>
struct is_forward_iterator
{
constexpr static bool value = is_forward_iterator_category_v<typename std::iterator_traits<Iter>::iterator_category>;
};
template<typename Iter>
struct is_bidirectional_iterator
{
constexpr static bool value = is_bidirectional_iterator_category_v<typename std::iterator_traits<Iter>::iterator_category>;
};
template<typename Iter>
struct is_random_access_iterator
{
constexpr static bool value = is_random_access_iterator_category_v<typename std::iterator_traits<Iter>::iterator_category>;
};
template<typename Iter>
inline constexpr bool is_input_iterator_v = is_input_iterator<Iter>::value;
template<typename Iter>
inline constexpr bool is_forward_iterator_v = is_forward_iterator<Iter>::value;
template<typename Iter>
inline constexpr bool is_bidirectional_iterator_v = is_bidirectional_iterator<Iter>::value;
template<typename Iter>
inline constexpr bool is_random_access_iterator_v = is_random_access_iterator<Iter>::value;
template<typename Iter>
inline constexpr bool is_bidirectional_or_better_v = is_bidirectional_iterator_v<Iter> || is_random_access_iterator_v<Iter>;
template<typename... Iter>
struct lowest_iterator_category
{
using type = std::common_type_t<typename std::iterator_traits<Iter>::iterator_category...>;
};
}
#endif //BLT_META_ITERATOR_H