It is possible to omit the type for the closure's parameter and return type. The following lines show a simplified version of the previously shown code that generates the same result. Note that the closure code is really simplified and doesn't even include the return statement because it uses implicit return. Swift evaluates the code we write after the
in keyword and returns its evaluation as if we included the return statement before the expression. Swift infers the return type. We just have to replace the existing code for the
filteredBy method in the
NumbersWorker class with the new code. The code file for the sample is included in the
open func filteredBy(condition: ...