c++-ABC-e6c4a5a21b3b7335.yaml

---
prelude: >
    The entire C++ library has been rewritten for performance and consistency.
features:
  - New ``dimod::abc::QuadraticModelBase`` abstract base class.
  - Better performance for linear models.
upgrade:
  - Rewrite ``dimod::QuadraticModelBase`` and move it to ``dimod::abc::QuadraticModelBase`` in ``abc.h``.
  - Move ``dimod::Vartype``, ``dimod::vartype_info``, and ``dimod::vartype_limits` to ``vartypes.h``.
  - Remove the ``dimod::Neighborhood`` class.
  - Remove ``iterators.h``.
  - Move ``dimod::BinaryQuadraticModel`` to ``binary_quadratic_model.h``.