mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
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f40ee0a2ff
rename fix random/random_iterator.hpp -> random/iterator.hpp
157 lines
4.7 KiB
C++
157 lines
4.7 KiB
C++
#ifndef SPROUT_ITERATOR_GENERATOR_ITERATOR_HPP
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#define SPROUT_ITERATOR_GENERATOR_ITERATOR_HPP
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#include <cstddef>
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#include <iterator>
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#include <utility>
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#include <stdexcept>
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#include <type_traits>
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#include <sprout/config.hpp>
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#include <sprout/generator/functions.hpp>
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namespace sprout {
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//
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// generator_iterator
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//
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template<typename Generator>
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class generator_iterator
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: public std::iterator<
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std::forward_iterator_tag,
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typename std::remove_reference<decltype(sprout::generators::generated_value(std::declval<Generator>()))>::type,
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std::ptrdiff_t,
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typename std::remove_reference<decltype(sprout::generators::generated_value(std::declval<Generator>()))>::type*,
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decltype(sprout::generators::generated_value(std::declval<Generator>()))
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>
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{
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public:
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typedef Generator generator_type;
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typedef std::forward_iterator_tag iterator_category;
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typedef decltype(sprout::generators::generated_value(std::declval<Generator>())) reference;
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typedef typename std::remove_reference<reference>::type value_type;
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typedef std::ptrdiff_t difference_type;
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typedef value_type* pointer;
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private:
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generator_type gen_;
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difference_type count_;
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public:
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SPROUT_CONSTEXPR generator_iterator()
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: gen_()
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, count_()
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{}
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explicit SPROUT_CONSTEXPR generator_iterator(
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generator_type const& gen,
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difference_type count = -1
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)
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: gen_(gen)
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, count_(count)
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{}
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generator_type& generator() {
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return gen_;
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}
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SPROUT_CONSTEXPR generator_type const& generator() const {
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return gen_;
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}
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SPROUT_CONSTEXPR difference_type count() const {
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return count_;
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}
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SPROUT_CONSTEXPR generator_iterator operator()() const {
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return count_ != 0
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? generator_iterator(sprout::generators::next_generator(gen_)(), count_ > 0 ? count_ - 1 : count_)
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: throw std::out_of_range("generator_iterator<>: increment at out of range")
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;
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}
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SPROUT_CONSTEXPR generator_iterator next() const {
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return (*this)();
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}
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SPROUT_CONSTEXPR reference generated_value() const {
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return sprout::generators::generated_value(gen_);
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}
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SPROUT_CONSTEXPR generator_iterator next_generator() const {
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return (*this)();
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}
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void swap(generator_iterator& other) {
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using std::swap;
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swap(gen_, other.gen_);
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swap(count_, other.count_);
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}
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friend SPROUT_CONSTEXPR bool operator==(generator_iterator const& lhs, generator_iterator const& rhs) {
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return lhs.count_ == rhs.count_;
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}
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friend SPROUT_CONSTEXPR bool operator!=(generator_iterator const& lhs, generator_iterator const& rhs) {
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return !(lhs == rhs);
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}
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friend SPROUT_CONSTEXPR bool operator<(generator_iterator const& lhs, generator_iterator const& rhs) {
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typedef typename std::make_unsigned<difference_type>::type unsigned_type;
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return static_cast<unsigned_type>(lhs.count_) > static_cast<unsigned_type>(rhs.count_);
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}
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friend SPROUT_CONSTEXPR bool operator>(generator_iterator const& lhs, generator_iterator const& rhs) {
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return rhs < lhs;
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}
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friend SPROUT_CONSTEXPR bool operator<=(generator_iterator const& lhs, generator_iterator const& rhs) {
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return !(rhs < lhs);
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}
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friend SPROUT_CONSTEXPR bool operator>=(generator_iterator const& lhs, generator_iterator const& rhs) {
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return !(lhs < rhs);
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}
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SPROUT_CONSTEXPR reference operator*() const {
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return count_ != 0
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? sprout::generators::generated_value(gen_)
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: (throw std::out_of_range("generator_iterator<>: dereference at out of range"), gen_.result())
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;
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}
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SPROUT_CONSTEXPR pointer operator->() const {
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return &*(*this);
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}
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generator_iterator& operator++() {
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generator_iterator temp((*this)());
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temp.swap(*this);
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return *this;
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}
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generator_iterator operator++(int) {
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generator_iterator result(*this);
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++*this;
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return result;
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}
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friend SPROUT_CONSTEXPR difference_type operator-(generator_iterator const& lhs, generator_iterator const& rhs) {
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return rhs.count_ - lhs.count_;
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}
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};
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//
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// swap
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//
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template<typename Generator>
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void swap(
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sprout::generator_iterator<Generator>& lhs,
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sprout::generator_iterator<Generator>& rhs
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)
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{
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lhs.swap(rhs);
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}
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//
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// iterator_distance
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//
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template<typename Generator>
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inline SPROUT_CONSTEXPR typename std::iterator_traits<sprout::generator_iterator<Generator> >::difference_type
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iterator_distance(
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sprout::generator_iterator<Generator> first,
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sprout::generator_iterator<Generator> last
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)
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{
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return last - first;
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}
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//
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// iterator_next
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//
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template<typename Generator>
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SPROUT_CONSTEXPR sprout::generator_iterator<Generator> iterator_next(
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sprout::generator_iterator<Generator> const& it
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)
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{
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return it.next();
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}
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} // namespace sprout
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#endif // #ifndef SPROUT_ITERATOR_GENERATOR_ITERATOR_HPP
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