Marcel truth

A truthy value is a value that is considered to be true for an if, or a while.

A falsey value is a value that is considered false in those places.

The only falsey values are the following:

• false
• null
• a Boolean instance whose value is false
• Optional.empty(), OptionalInt.empty(), OptionalDouble.empty(), OptionalLong.empty()
• An empty collection
• An empty array
• An empty Map
• An empty String
• A Matcher who's find() method would return false
• A File who's exists() method would return false
• A failure Result
• An object implementing MarcelTruth who's isTruthy() method would return false

Any other value is truthy.