67 lines
1.9 KiB
C++
67 lines
1.9 KiB
C++
#pragma once
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namespace fmri
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{
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/**
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* Iterable that produces a specific range of integers.
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*
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* Useful to make an automatically typed for loop over an unknown integer type.
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*
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* @tparam T The integer type to use.
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*/
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template<class T>
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class Range
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{
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private:
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T start_;
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T end_;
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public:
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/**
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* Construct a range from 0 to num, non inclusive.
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*
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* @param num
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*/
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constexpr explicit Range(const T &num) : start_(0), end_(num) {};
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/**
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* Construct a range from start to end, non inclusive.
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*
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* @param start
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* @param end
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*/
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constexpr Range(const T &start, const T &end) : start_(start), end_(end) {};
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class Iter
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{
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private:
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T cur_;
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public:
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constexpr explicit Iter(const T &cur) : cur_(cur)
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{};
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typedef std::bidirectional_iterator_tag iterator_category;
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typedef T value_type;
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typedef typename std::make_signed<T>::type difference_type;
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typedef T& reference;
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typedef T* pointer;
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constexpr bool operator!=(const Iter& o) { return o.cur_ != cur_; }
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constexpr Iter&operator++() { ++cur_; return *this; }
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constexpr Iter&operator--() { --cur_; return *this; }
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constexpr const T &operator*() { return cur_; }
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};
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typedef Iter const_iterator;
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typedef std::reverse_iterator<Iter> const_reverse_iterator;
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constexpr const_iterator begin() const { return Iter(start_); }
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constexpr const_iterator end() const { return Iter(end_); }
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constexpr const_reverse_iterator rbegin() const { return std::make_reverse_iterator(end()); }
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constexpr const_reverse_iterator rend() const { return std::make_reverse_iterator(begin()); }
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};
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}
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