Moose types

• See Moose::Util::TypeConstraints

  Any
  Item
      Bool
      Maybe[`a]
      Undef
      Defined
          Value
              Num
                Int
              Str
                ClassName
          Ref
              ScalarRef
              ArrayRef[`a]
              HashRef[`a]
              CodeRef
              RegexpRef
              GlobRef
                FileHandle
              Object
                  Role

• [`a] can be anything
• Maybe[Str]
• A string, or undefined
• ArrayRef[Str]
• An array of strings
• HashRef[Num]
• A hash with Num values (keys are always Str, this is still Perl)