[zionic]

>It's a bad example.

It's a bad example enabled by a bad language feature. Just you wait until answers on stack overflow, sample code, and open source libs are littered with these "bad examples".

Meanwhile, this example is terrible. There is no real need for callAsFunction in your example when you could have added a simple named function on the object to do so. Better yet, you could define a protocol and make sure your layer conforms to said protocol.

[chc]

There is an argument to be made against features that are more likely to cause harm than good (i.e. "footguns"), but I don't think this example of using it poorly sheds any light on whether that's the case here. You could, with roughly the same level of rigor, argue that allowing people to name variables is bad by constructing an example with variables named CONFUSING, CONFUSlNG and CONFUS1NG.

Any feature, no matter how good, can be misused. Pointing that out about a specific feature isn't interesting, because it is true of every feature. And the absence of nearly any feature can be worked around, as ultimately all these features compile down to machine code, which doesn't have most features of a high-level language, so the existence of a workaround is also not a very compelling argument.

[smabie]

Scala has the same thing with apply() and it works great, allowing the language to have a consistant syntax for function calls, object creation, and array index access.