359 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C++
		
	
	
			
		
		
	
	
			359 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C++
		
	
	
| /*
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|     tests/test_sequences_and_iterators.cpp -- supporting Pythons' sequence protocol, iterators,
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|     etc.
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| 
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|     Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
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| 
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|     All rights reserved. Use of this source code is governed by a
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|     BSD-style license that can be found in the LICENSE file.
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| */
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| 
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| #include "pybind11_tests.h"
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| #include "constructor_stats.h"
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| #include <pybind11/operators.h>
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| #include <pybind11/stl.h>
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| 
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| #include <algorithm>
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| 
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| template<typename T>
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| class NonZeroIterator {
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|     const T* ptr_;
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| public:
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|     NonZeroIterator(const T* ptr) : ptr_(ptr) {}
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|     const T& operator*() const { return *ptr_; }
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|     NonZeroIterator& operator++() { ++ptr_; return *this; }
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| };
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| 
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| class NonZeroSentinel {};
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| 
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| template<typename A, typename B>
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| bool operator==(const NonZeroIterator<std::pair<A, B>>& it, const NonZeroSentinel&) {
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|     return !(*it).first || !(*it).second;
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| }
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| 
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| template <typename PythonType>
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| py::list test_random_access_iterator(PythonType x) {
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|     if (x.size() < 5)
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|         throw py::value_error("Please provide at least 5 elements for testing.");
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| 
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|     auto checks = py::list();
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|     auto assert_equal = [&checks](py::handle a, py::handle b) {
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|         auto result = PyObject_RichCompareBool(a.ptr(), b.ptr(), Py_EQ);
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|         if (result == -1) { throw py::error_already_set(); }
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|         checks.append(result != 0);
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|     };
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| 
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|     auto it = x.begin();
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|     assert_equal(x[0], *it);
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|     assert_equal(x[0], it[0]);
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|     assert_equal(x[1], it[1]);
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| 
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|     assert_equal(x[1], *(++it));
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|     assert_equal(x[1], *(it++));
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|     assert_equal(x[2], *it);
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|     assert_equal(x[3], *(it += 1));
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|     assert_equal(x[2], *(--it));
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|     assert_equal(x[2], *(it--));
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|     assert_equal(x[1], *it);
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|     assert_equal(x[0], *(it -= 1));
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| 
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|     assert_equal(it->attr("real"), x[0].attr("real"));
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|     assert_equal((it + 1)->attr("real"), x[1].attr("real"));
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| 
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|     assert_equal(x[1], *(it + 1));
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|     assert_equal(x[1], *(1 + it));
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|     it += 3;
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|     assert_equal(x[1], *(it - 2));
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| 
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|     checks.append(static_cast<std::size_t>(x.end() - x.begin()) == x.size());
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|     checks.append((x.begin() + static_cast<std::ptrdiff_t>(x.size())) == x.end());
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|     checks.append(x.begin() < x.end());
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| 
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|     return checks;
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| }
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| 
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| TEST_SUBMODULE(sequences_and_iterators, m) {
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|     // test_sliceable
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|     class Sliceable{
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|     public:
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|       Sliceable(int n): size(n) {}
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|       int start,stop,step;
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|       int size;
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|     };
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|     py::class_<Sliceable>(m,"Sliceable")
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|         .def(py::init<int>())
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|         .def("__getitem__",[](const Sliceable &s, py::slice slice) {
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|           ssize_t start, stop, step, slicelength;
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|           if (!slice.compute(s.size, &start, &stop, &step, &slicelength))
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|               throw py::error_already_set();
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|           int istart = static_cast<int>(start);
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|           int istop =  static_cast<int>(stop);
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|           int istep =  static_cast<int>(step);
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|           return std::make_tuple(istart,istop,istep);
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|         })
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|         ;
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| 
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|     // test_sequence
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|     class Sequence {
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|     public:
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|         Sequence(size_t size) : m_size(size) {
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|             print_created(this, "of size", m_size);
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|             m_data = new float[size];
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|             memset(m_data, 0, sizeof(float) * size);
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|         }
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|         Sequence(const std::vector<float> &value) : m_size(value.size()) {
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|             print_created(this, "of size", m_size, "from std::vector");
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|             m_data = new float[m_size];
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|             memcpy(m_data, &value[0], sizeof(float) * m_size);
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|         }
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|         Sequence(const Sequence &s) : m_size(s.m_size) {
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|             print_copy_created(this);
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|             m_data = new float[m_size];
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|             memcpy(m_data, s.m_data, sizeof(float)*m_size);
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|         }
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|         Sequence(Sequence &&s) : m_size(s.m_size), m_data(s.m_data) {
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|             print_move_created(this);
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|             s.m_size = 0;
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|             s.m_data = nullptr;
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|         }
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| 
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|         ~Sequence() { print_destroyed(this); delete[] m_data; }
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| 
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|         Sequence &operator=(const Sequence &s) {
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|             if (&s != this) {
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|                 delete[] m_data;
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|                 m_size = s.m_size;
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|                 m_data = new float[m_size];
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|                 memcpy(m_data, s.m_data, sizeof(float)*m_size);
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|             }
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|             print_copy_assigned(this);
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|             return *this;
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|         }
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| 
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|         Sequence &operator=(Sequence &&s) {
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|             if (&s != this) {
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|                 delete[] m_data;
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|                 m_size = s.m_size;
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|                 m_data = s.m_data;
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|                 s.m_size = 0;
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|                 s.m_data = nullptr;
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|             }
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|             print_move_assigned(this);
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|             return *this;
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|         }
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| 
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|         bool operator==(const Sequence &s) const {
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|             if (m_size != s.size()) return false;
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|             for (size_t i = 0; i < m_size; ++i)
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|                 if (m_data[i] != s[i])
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|                     return false;
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|             return true;
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|         }
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|         bool operator!=(const Sequence &s) const { return !operator==(s); }
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| 
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|         float operator[](size_t index) const { return m_data[index]; }
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|         float &operator[](size_t index) { return m_data[index]; }
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| 
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|         bool contains(float v) const {
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|             for (size_t i = 0; i < m_size; ++i)
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|                 if (v == m_data[i])
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|                     return true;
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|             return false;
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|         }
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| 
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|         Sequence reversed() const {
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|             Sequence result(m_size);
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|             for (size_t i = 0; i < m_size; ++i)
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|                 result[m_size - i - 1] = m_data[i];
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|             return result;
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|         }
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| 
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|         size_t size() const { return m_size; }
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| 
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|         const float *begin() const { return m_data; }
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|         const float *end() const { return m_data+m_size; }
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| 
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|     private:
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|         size_t m_size;
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|         float *m_data;
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|     };
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|     py::class_<Sequence>(m, "Sequence")
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|         .def(py::init<size_t>())
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|         .def(py::init<const std::vector<float>&>())
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|         /// Bare bones interface
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|         .def("__getitem__", [](const Sequence &s, size_t i) {
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|             if (i >= s.size()) throw py::index_error();
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|             return s[i];
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|         })
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|         .def("__setitem__", [](Sequence &s, size_t i, float v) {
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|             if (i >= s.size()) throw py::index_error();
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|             s[i] = v;
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|         })
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|         .def("__len__", &Sequence::size)
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|         /// Optional sequence protocol operations
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|         .def("__iter__", [](const Sequence &s) { return py::make_iterator(s.begin(), s.end()); },
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|                          py::keep_alive<0, 1>() /* Essential: keep object alive while iterator exists */)
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|         .def("__contains__", [](const Sequence &s, float v) { return s.contains(v); })
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|         .def("__reversed__", [](const Sequence &s) -> Sequence { return s.reversed(); })
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|         /// Slicing protocol (optional)
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|         .def("__getitem__", [](const Sequence &s, py::slice slice) -> Sequence* {
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|             size_t start, stop, step, slicelength;
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|             if (!slice.compute(s.size(), &start, &stop, &step, &slicelength))
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|                 throw py::error_already_set();
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|             auto *seq = new Sequence(slicelength);
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|             for (size_t i = 0; i < slicelength; ++i) {
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|                 (*seq)[i] = s[start]; start += step;
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|             }
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|             return seq;
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|         })
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|         .def("__setitem__", [](Sequence &s, py::slice slice, const Sequence &value) {
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|             size_t start, stop, step, slicelength;
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|             if (!slice.compute(s.size(), &start, &stop, &step, &slicelength))
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|                 throw py::error_already_set();
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|             if (slicelength != value.size())
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|                 throw std::runtime_error("Left and right hand size of slice assignment have different sizes!");
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|             for (size_t i = 0; i < slicelength; ++i) {
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|                 s[start] = value[i]; start += step;
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|             }
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|         })
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|         /// Comparisons
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|         .def(py::self == py::self)
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|         .def(py::self != py::self)
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|         // Could also define py::self + py::self for concatenation, etc.
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|         ;
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| 
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|     // test_map_iterator
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|     // Interface of a map-like object that isn't (directly) an unordered_map, but provides some basic
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|     // map-like functionality.
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|     class StringMap {
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|     public:
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|         StringMap() = default;
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|         StringMap(std::unordered_map<std::string, std::string> init)
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|             : map(std::move(init)) {}
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| 
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|         void set(std::string key, std::string val) { map[key] = val; }
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|         std::string get(std::string key) const { return map.at(key); }
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|         size_t size() const { return map.size(); }
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|     private:
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|         std::unordered_map<std::string, std::string> map;
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|     public:
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|         decltype(map.cbegin()) begin() const { return map.cbegin(); }
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|         decltype(map.cend()) end() const { return map.cend(); }
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|     };
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|     py::class_<StringMap>(m, "StringMap")
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|         .def(py::init<>())
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|         .def(py::init<std::unordered_map<std::string, std::string>>())
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|         .def("__getitem__", [](const StringMap &map, std::string key) {
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|                 try { return map.get(key); }
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|                 catch (const std::out_of_range&) {
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|                     throw py::key_error("key '" + key + "' does not exist");
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|                 }
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|         })
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|         .def("__setitem__", &StringMap::set)
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|         .def("__len__", &StringMap::size)
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|         .def("__iter__", [](const StringMap &map) { return py::make_key_iterator(map.begin(), map.end()); },
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|                 py::keep_alive<0, 1>())
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|         .def("items", [](const StringMap &map) { return py::make_iterator(map.begin(), map.end()); },
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|                 py::keep_alive<0, 1>())
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|         ;
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| 
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|     // test_generalized_iterators
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|     class IntPairs {
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|     public:
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|         IntPairs(std::vector<std::pair<int, int>> data) : data_(std::move(data)) {}
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|         const std::pair<int, int>* begin() const { return data_.data(); }
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|     private:
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|         std::vector<std::pair<int, int>> data_;
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|     };
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|     py::class_<IntPairs>(m, "IntPairs")
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|         .def(py::init<std::vector<std::pair<int, int>>>())
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|         .def("nonzero", [](const IntPairs& s) {
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|                 return py::make_iterator(NonZeroIterator<std::pair<int, int>>(s.begin()), NonZeroSentinel());
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|         }, py::keep_alive<0, 1>())
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|         .def("nonzero_keys", [](const IntPairs& s) {
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|             return py::make_key_iterator(NonZeroIterator<std::pair<int, int>>(s.begin()), NonZeroSentinel());
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|         }, py::keep_alive<0, 1>())
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|         ;
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| 
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| 
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| #if 0
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|     // Obsolete: special data structure for exposing custom iterator types to python
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|     // kept here for illustrative purposes because there might be some use cases which
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|     // are not covered by the much simpler py::make_iterator
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| 
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|     struct PySequenceIterator {
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|         PySequenceIterator(const Sequence &seq, py::object ref) : seq(seq), ref(ref) { }
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| 
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|         float next() {
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|             if (index == seq.size())
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|                 throw py::stop_iteration();
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|             return seq[index++];
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|         }
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| 
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|         const Sequence &seq;
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|         py::object ref; // keep a reference
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|         size_t index = 0;
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|     };
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| 
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|     py::class_<PySequenceIterator>(seq, "Iterator")
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|         .def("__iter__", [](PySequenceIterator &it) -> PySequenceIterator& { return it; })
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|         .def("__next__", &PySequenceIterator::next);
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| 
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|     On the actual Sequence object, the iterator would be constructed as follows:
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|     .def("__iter__", [](py::object s) { return PySequenceIterator(s.cast<const Sequence &>(), s); })
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| #endif
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| 
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|     // test_python_iterator_in_cpp
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|     m.def("object_to_list", [](py::object o) {
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|         auto l = py::list();
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|         for (auto item : o) {
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|             l.append(item);
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|         }
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|         return l;
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|     });
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| 
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|     m.def("iterator_to_list", [](py::iterator it) {
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|         auto l = py::list();
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|         while (it != py::iterator::sentinel()) {
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|             l.append(*it);
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|             ++it;
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|         }
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|         return l;
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|     });
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| 
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|     // test_sequence_length: check that Python sequences can be converted to py::sequence.
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|     m.def("sequence_length", [](py::sequence seq) { return seq.size(); });
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| 
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|     // Make sure that py::iterator works with std algorithms
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|     m.def("count_none", [](py::object o) {
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|         return std::count_if(o.begin(), o.end(), [](py::handle h) { return h.is_none(); });
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|     });
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| 
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|     m.def("find_none", [](py::object o) {
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|         auto it = std::find_if(o.begin(), o.end(), [](py::handle h) { return h.is_none(); });
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|         return it->is_none();
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|     });
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| 
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|     m.def("count_nonzeros", [](py::dict d) {
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|        return std::count_if(d.begin(), d.end(), [](std::pair<py::handle, py::handle> p) {
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|            return p.second.cast<int>() != 0;
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|        });
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|     });
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| 
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|     m.def("tuple_iterator", &test_random_access_iterator<py::tuple>);
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|     m.def("list_iterator", &test_random_access_iterator<py::list>);
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|     m.def("sequence_iterator", &test_random_access_iterator<py::sequence>);
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| 
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|     // test_iterator_passthrough
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|     // #181: iterator passthrough did not compile
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|     m.def("iterator_passthrough", [](py::iterator s) -> py::iterator {
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|         return py::make_iterator(std::begin(s), std::end(s));
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|     });
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| 
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|     // test_iterator_rvp
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|     // #388: Can't make iterators via make_iterator() with different r/v policies
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|     static std::vector<int> list = { 1, 2, 3 };
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|     m.def("make_iterator_1", []() { return py::make_iterator<py::return_value_policy::copy>(list); });
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|     m.def("make_iterator_2", []() { return py::make_iterator<py::return_value_policy::automatic>(list); });
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| }
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