optparse-generic/CHANGELOG.md

1.3.0

• BREAKING CHANGE: New metavar method for ParseField class
  • This field simplifies customizing ParseField instances
    • Now you usually only need to override metavar now or possibly also readField, whereas the default behavior for parseField should work more often
  • This is only a breaking change for data types that use the default implementation of ParseField but do not derive Typeable
  • You can migrate existing code that doesn't compile by just explicitly specifying what the metavar field should be