Function TestTupleRangeAPI

Common/Core/Testing/Cxx/ExampleDataArrayRangeAPI.cxx:27–340

template <typename ArrayT>
void TestTupleRangeAPI(ArrayT* someArray)
{
  // TupleRanges have a two-step hierarchy of iterators and references. The
  // first layer encapsulates the concept of tuples, and the second layer
  // provides access to the components in a tuple. The following code shows
  // how these objects (TupleRange, TupleIterator, TupleReference,
  // ComponentIterator, ComponentReference) can be used.

  // A TupleRange can be restricted to a subset of the array's data by passing
  // explicit start/end values to vtk::DataArrayTupleRange:
  {
    auto subRange = vtk::DataArrayTupleRange(someArray, 2, 8);
    // Iterates over tuples 2-7 (inclusive).
    for (auto tupleRef : subRange)
    {
      std::cout << "Tuple: ";
      for (auto compRef : tupleRef)
      {
        std::cout << compRef << " ";
      }
      std::cout << "\n";
    }
  }

  // If the exact number of components in a tuple is known at compile-time,
  // this can be passed as a template argument to vtk::DataArrayTupleRange.
  // This will enable additional compiler optimizations to improve performance.
  {
    auto optimizedRange = vtk::DataArrayTupleRange<4>(someArray);
    // Accessing data in optimizedRange will be more efficient as variables
    // like array strides are made available to the compiler.
    for (auto tupleRef : optimizedRange)
    {
      std::cout << "Tuple: ";
      for (auto compRef : tupleRef)
      {
        std::cout << compRef << " ";
      }
      std::cout << "\n";
    }
  }

  // Both tuple size and subrange information can be used simultaneously:
  {
    auto optimizedSubRange = vtk::DataArrayTupleRange<4>(someArray, 2, 8);
    for (auto tupleRef : optimizedSubRange)
    {
      std::cout << "Tuple: ";
      for (auto compRef : tupleRef)
      {
        std::cout << compRef << " ";
      }
      std::cout << "\n";
    }
  }

  // If tuple size is unknown and the range should encompass the full length of
  // the array, simply pass in the array with no template arguments: