[be3416d] | 1 | #include "base.hpp" |
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[9cb4fc8] | 2 | |
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[be3416d] | 3 | #include <algorithm> |
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| 4 | #include <iterator> |
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| 5 | #include <vector> |
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[9cb4fc8] | 6 | |
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| 7 | template<typename T> |
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| 8 | struct cor_range { |
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| 9 | struct promise_type { |
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| 10 | T _value; |
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| 11 | |
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| 12 | cor_range get_return_object() { |
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| 13 | return cor_range(std::experimental::coroutine_handle<promise_type>::from_promise(*this)); |
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| 14 | } |
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| 15 | |
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[be3416d] | 16 | auto initial_suspend() { return suspend_always(); } |
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| 17 | auto final_suspend() { return suspend_always(); } |
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[9cb4fc8] | 18 | |
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| 19 | void return_value(T value) { |
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| 20 | _value = value; |
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| 21 | } |
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| 22 | |
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| 23 | auto yield_value(T value) { |
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| 24 | _value = value; |
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| 25 | return suspend_always(); |
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| 26 | } |
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| 27 | |
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| 28 | void unhandled_exception() {} |
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| 29 | }; |
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| 30 | |
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| 31 | std::experimental::coroutine_handle<promise_type> _coroutine = nullptr; |
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| 32 | |
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| 33 | explicit cor_range(std::experimental::coroutine_handle<promise_type> coroutine) |
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| 34 | : _coroutine(coroutine) |
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| 35 | {} |
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| 36 | |
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| 37 | ~cor_range() { |
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| 38 | if(_coroutine) { _coroutine.destroy(); } |
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| 39 | } |
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| 40 | |
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| 41 | cor_range() = default; |
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| 42 | cor_range(cor_range const &) = delete; |
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| 43 | cor_range& operator=(cor_range const &) = delete; |
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| 44 | |
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| 45 | cor_range(cor_range&& other) { |
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| 46 | std::swap(_coroutine, other._coroutine); |
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| 47 | } |
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| 48 | |
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| 49 | cor_range& operator=(cor_range&& other) { |
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| 50 | if(&other != this) { |
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| 51 | _coroutine = other._coroutine; |
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| 52 | other._coroutine = nullptr; |
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| 53 | } |
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| 54 | return *this; |
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| 55 | } |
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| 56 | |
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| 57 | T next() { |
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| 58 | _coroutine.resume(); |
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| 59 | return _coroutine.promise()._value; |
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| 60 | } |
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[be3416d] | 61 | |
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| 62 | struct iterator : std::iterator<std::input_iterator_tag, T> { |
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| 63 | std::experimental::coroutine_handle<promise_type> _coroutine = nullptr; |
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| 64 | |
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| 65 | iterator() = default; |
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| 66 | explicit iterator(std::experimental::coroutine_handle<promise_type> coroutine) |
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| 67 | : _coroutine(coroutine) |
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| 68 | {} |
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| 69 | |
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| 70 | iterator& operator++() { |
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| 71 | _coroutine.resume(); |
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| 72 | return *this; |
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| 73 | } |
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| 74 | |
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| 75 | T const & operator*() const { |
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| 76 | return _coroutine.promise()._value; |
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| 77 | } |
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| 78 | }; |
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| 79 | |
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| 80 | iterator begin() { |
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| 81 | if(_coroutine) { |
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| 82 | _coroutine.resume(); |
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| 83 | if(_coroutine.done()) { return end(); } |
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| 84 | } |
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| 85 | |
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| 86 | return iterator{ _coroutine }; |
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| 87 | } |
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| 88 | |
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| 89 | iterator end() { return iterator{}; } |
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[9cb4fc8] | 90 | }; |
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| 91 | |
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| 92 | cor_range<int> fib() { |
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| 93 | int fn; |
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| 94 | fn = 0; int fn1 = fn; co_yield fn; |
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| 95 | fn = 1; int fn2 = fn1; fn1 = fn; co_yield fn; |
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| 96 | for(;;) { |
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| 97 | fn = fn1 + fn2; fn2 = fn1; fn1 = fn; co_yield fn; |
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| 98 | } |
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| 99 | } |
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| 100 | |
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| 101 | int main() { |
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[be3416d] | 102 | { |
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| 103 | auto f1 = fib(); |
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| 104 | auto f2 = fib(); |
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| 105 | for(int i = 0; i < 10; i++) { |
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| 106 | std::cout << f1.next() << " " << f2.next() << std::endl; |
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| 107 | } |
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| 108 | } |
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| 109 | |
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| 110 | { |
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| 111 | auto f1 = fib(); |
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| 112 | std::vector<int> fibs; |
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| 113 | std::copy_n(f1.begin(), 10, std::back_inserter(fibs)); |
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| 114 | |
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| 115 | for(auto i : fibs) { |
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| 116 | std::cout << i << std::endl; |
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| 117 | } |
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[9cb4fc8] | 118 | } |
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| 119 | } |
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