0.4.3

New Features

• Implement C++ operator<=>(const Update&, const Update&) and
  operator==(const Update&, const Update&). This allows Update to
  be used with std::ranges::stable_sort().
• Add a new Cython extension type, _Graph. The _Graph class is
  responsible for managing a C++ dwave::optimization::Graph. Also
  make Model a Python class that inherits from _Graph, rather than
  a Cython extension type.
• Add C++ DivideNode and Python Divide symbol, and overriding
  __truediv__. Divide propagates the division of its
  predecessors element-wise. Note that predecessors of Divide must be
  either strictly positive or strictly negative.
• Add C++ SquareRootNode and Python SquareRoot symbol.
  SquareRoot propagates the square-root(s) of its predecessor
  element-wise.
• Add const and non-const versions of C++ array iterators.
• Make C++ array iterators random access iterators. Previously they
  were bidirectional iterators.

Upgrade Notes

• Remove C++ Update::equals(const Update&) method in favour of
  operator==(const Update&, const Update&).
• It is no longer possible to
  from dwave.optimization.model cimport Model. Instead, importers
  should from dwave.optimization.model cimport _Graph. A _Graph
  has most of the functionality that a Model did, although most of
  the symbol construction methods have been kept on Model.
• The dwave::optimization::ArrayIterator class has been moved. It
  can now be found as a nested class in the Array, i.e.
  dwave::optimization::Array::const_iterator.