XO0401: value of the wrong type; only three implicit conversions exist

The value’s type is not the expected one. Xo converts implicitly in exactly three cases, each only where the target type is known: T to T?, a value to an interface it implements, and an error at ? to the enclosing error type. Everything else is explicit, including all numeric conversions (Float(i)) and newtypes (Email(s)). Branches of if and match must already agree; annotate the binding to give them an expected type. See core 2.10.

Example

fn f(i: Int) -> Float { i }

Fix

fn f(i: Int) -> Float { Float(i) }

Run xo explain XO0401 for this text in a terminal, or see section 10.6 of the specification.