added type assertion example

[kevin-kho]

addresses issue #523

[eliben]

Thanks for the PR.

I would simplify it more. We don't need the circum method.

I'd just create a function called something like detectCircle that takes a geometry and prints out its radius it's a cirlce. The comment should clarify that this is done if we want to explicitly check the runtime type of the value; the comment should also point to the switch example for an alternative approach.

[kevin-kho]

Thanks for the PR.

I would simplify it more. We don't need the circum method.

I'd just create a function called something like detectCircle that takes a geometry and prints out its radius it's a cirlce. The comment should clarify that this is done if we want to explicitly check the runtime type of the value; the comment should also point to the switch example for an alternative approach.

addressed in commit 6d59536

[eliben]

Thank you - this is close enough to what I want that I'll go ahead and merge it. I'll tweak it a bit before republishing