NDIter
======

.. cpp:class:: numpy::NDIter

   numpy C++ class.

Example
-------

.. code-block:: cpp

   #include <numpy/np_ndarray.h>
   using namespace numpy;

   // Use NDIter
   NDIter obj;
   // ... operations ...

Constructors
------------

.. list-table::
   :widths: 55 25 20
   :header-rows: 1

   * - Signature
     - Location
     - Example
   * - ``NDIter(const NDArray<T>&array, boolc_order = true)``
     - NP_NDITER.H:40
     - 
   * - ``NDIter(const NDArray<T>&array, const std::vector<int>&order)``
     - NP_NDITER.H:62
     - 

Operators
---------

.. list-table::
   :widths: 40 25 15 20
   :header-rows: 1

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``value_type operator\*()``
     - value_type
     - NP_NDITER.H:86
     - 
   * - ``NDIter & operator++()``
     - NDIter &
     - NP_NDITER.H:97
     - 
   * - ``NDIter operator++(int)``
     - NDIter
     - NP_NDITER.H:121
     - 
   * - ``bool operator==(const NDIter &other)``
     - bool
     - NP_NDITER.H:128
     - 
   * - ``bool operator!=(const NDIter &other)``
     - bool
     - NP_NDITER.H:139
     - 

Type Checking
-------------

.. list-table::
   :widths: 40 20 15 25
   :header-rows: 1

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``bool is_finished()``
     - bool
     - NP_NDITER.H:144
     - :ref:`View <example-nditer-is_finished-0>`

Other Methods
-------------

.. list-table::
   :widths: 40 20 15 25
   :header-rows: 1

   * - Signature
     - Return Type
     - Location
     - Example
   * - ``NDIter end(const NDArray<T>&array)``
     - NDIter
     - NP_NDITER.H:177
     - :ref:`View <example-nditer-end-1>`
   * - ``size_t flat_index()``
     - size_t
     - NP_NDITER.H:154
     - :ref:`View <example-nditer-flat_index-2>`
   * - ``const std::vector<size_t>& indices()``
     - const std::vector<size_t>&
     - NP_NDITER.H:149
     - :ref:`View <example-nditer-indices-3>`
   * - ``void reset()``
     - void
     - NP_NDITER.H:171
     - :ref:`View <example-nditer-reset-4>`


Code Examples
-------------

The following examples are extracted from the test suite.

.. _example-nditer-is_finished-0:

.. dropdown:: is_finished (np_test_2_all.cpp:3824)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 3814
      :emphasize-lines: 11

            for (size_t i = 0; i < 2; ++i) {
              for (size_t j = 0; j < 3; ++j) {
                arr.setElementAt({ i, j }, static_cast<double>(i * 3 + j));
              }
            }
      
            auto iter = nditer(arr);
            size_t count = 0;
            double expected_values[] = { 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 };
      
            for (; !iter.is_finished(); ++iter, ++count) {
              if (!(isApproxEqualMCO(*iter, expected_values[count]))) {
                  std::string description = std::string("testIterators():") + __FILE__ + ":" + std::to_string(__LINE__) + ": !(isApproxEqualMCO(*iter, expected_values[count]))";
                  std::cout << std::string("[FAIL] ") + description << std::endl;
                  throw std::runtime_error(description);
              }
            }
            if (!(count == 6)) {
                std::string description = std::string("testIterators():") + __FILE__ + ":" + std::to_string(__LINE__) + ": !(count == 6)";
                std::cout << std::string("[FAIL] ") + description << std::endl;
                throw std::runtime_error(description);

.. _example-nditer-end-1:

.. dropdown:: end (np_test_1_all.cpp:6171)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 6161
      :emphasize-lines: 11

          // Test sorted data generation
          std::vector<int> data = gen.generate(50, DataPattern::SORTED);
      
          if (!(data.size() == 50)) {
              std::string description = std::string("test_data_generator_sortedBenchmarkSorting():") + __FILE__ + ":" + std::to_string(__LINE__) + ": !(data.size() == 50)";
              std::cout << std::string("[FAIL] ") + description << std::endl;
              throw std::runtime_error(description);
          }
      
          // Verify data is sorted
          if (!(std::is_sorted(data.begin(), data.end()))) {
              std::string description = std::string("test_data_generator_sortedBenchmarkSorting():") + __FILE__ + ":" + std::to_string(__LINE__) + ": !(std::is_sorted(data.begin(), data.end()))";
              std::cout << std::string("[FAIL] ") + description << std::endl;
              throw std::runtime_error(description);
          }
      
          // std::cout << "Sorted data generation test passed" << std::endl;
      
          std::cout << " -> tests passed" << std::endl;
      }
      

.. _example-nditer-flat_index-2:

.. dropdown:: flat_index (np_test_5_all.cpp:11181)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 11171
      :emphasize-lines: 11

            for (size_t i = 0; i < 12; ++i) {
              arr.flat(i) = static_cast<int>(i);
            }
      
            // Test C-order iteration
            auto it = numpy::nditer(arr, true);
            int count = 0;
            while (!it.is_finished()) {
              int value = *it;
              auto indices = it.indices();
              size_t flat_idx = it.flat_index();
      
              // Verify correctness
              if (value != count || flat_idx != count) {
                std::cout << "  [FAIL] : in np_test_nditer_basic() : incorrect iteration order";
                throw std::runtime_error("np_test_nditer_basic failed: incorrect iteration order");
              }
      
              ++it;
              count++;
            }

.. _example-nditer-indices-3:

.. dropdown:: indices (np_test_1_all.cpp:47)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 37
      :emphasize-lines: 11

      
      using namespace numpy;
      using namespace numpy::benchmark;
      using namespace numpy::char_;
      
      // Helper functions for array comparison tests
      namespace {
          const double TOLERANCE = 1e-10;
      
          bool allTrue(const NDArray<bool>& arr) {
              std::vector<size_t> indices(arr.getShape().size(), 0);
              do {
                  if (!arr.getElementAt(indices)) {
                      return false;
                  }
              } while (incrementIndices(indices, arr.getShape()));
              return true;
          }
      
          bool allFalse(const NDArray<bool>& arr) {
              std::vector<size_t> indices(arr.getShape().size(), 0);

.. _example-nditer-reset-4:

.. dropdown:: reset (np_test_2_all.cpp:22610)
   :class-title: example-dropdown

   .. code-block:: cpp
      :linenos:
      :lineno-start: 22600
      :emphasize-lines: 11

            // Count iterations
            size_t outer_count = 0;
            size_t total_inner_count = 0;
            for (; !outer.is_finished(); ++outer) {
              size_t inner_count = 0;
              for (; !inner.is_finished(); ++inner) {
                inner_count++;
                total_inner_count++;
              }
              outer_count++;
              inner.reset();
            }
      
            if (outer_count != 3 || total_inner_count != 12) {
              std::cout << "  [FAIL] : Iteration counts incorrect";
              throw std::runtime_error("np_test_nested_iters_basic failed");
            }
      
            std::cout << " -> tests passed" << std::endl;
          }