optional 2.0

• NOT COMPATIBLE WITH VERSIONS 1.x
• Replace function some() with the type wrapper option()
• some() is now used to check the status of an optional object

optional 1.1

• Add a fall-through possibility for pattern matching with the fallthrough() function
• match_with() now returns a concatenation of return values from matched result-functions
• Values comparison in match_with() are now direct object comparisons instead of near equality checks

optional 1.0

Initial release