On 05/04/2018 12:54 PM, H. S. Teoh wrote:
This is a good point. However, I'm failing to see it as a big problem, because for it to be a problem in the first place, you have to have *deliberately* passed an object of said type into a function that expects that particular concept.
First of all, just to be clear in case I wasn't, I didn't mean that it's equally dangerous as globals, just that it's analogous. Globals are, of course, more dangerous.
Regarding the need to deliberately pass an object of said type to a function in order to cause a problem, that's not always true: It could be a matter of the compiler choosing the wrong overload. Or sticking it in the wrong parameter on certain templated functions.
Also, generally speaking, even without structural typing, the danger of passing an object of the wrong type to the wrong parameter/function/overload IS considered to be significant enough to help justify the whole premise of static typing. (Well, at least according to a certain faction of programmers, anyway ;) )
And ultimately, from a design standpoint, I really see no compelling reason *not* to require a formal declaration of "This deliberately implements isXYZ", other than just...some people just dislike it. So like, yea, we *can* get by without it...but...why would we want to?
