On Friday, January 18, 2019 8:34:22 AM MST Michael via Digitalmars-d-learn wrote: > On Friday, 18 January 2019 at 13:29:29 UTC, Adam D. Ruppe wrote: > > On Friday, 18 January 2019 at 12:27:17 UTC, Michael wrote: > >> This, to be, looks like quite the explicit conversion, no? > > > > Yeah, I agree. But the language is silly. I just leave the type > > out of foreach and explicitly cast it inside the body. > > Thank you all for the concise explanations and suggestions, I > think that's fairly straightforward. I thought perhaps I was > doing the sensible thing of dealing with the conversion inside > the foreach statement, but I guess not!
Well, you were really doing the equivalent of simply declaring a variable without a cast. e.g. int i = arr.length; rather than int i = cast(int)arr.length; In general, if the compiler treated giving the foreach variable an explicit type as being a cast, it would make it really easy to screw up and unknowingly give a different type than the actual type of the values and end up with an invisible cast, which could cause subtle bugs. IIRC, the only case where foreach treats giving an explict type as anything like a cast is when you're iterating over a string type, and you give a character type different from the character type of the string. In that case, it actually decodes the string from one Unicode encoding and encodes it in the other. Whether the language should have done that rather than requiring that a library solution be used is debatable (I believe that it far predates Phobos having the Unicode handling that it does now), but at least it can't result in stuff like silent truncation. Worst case, it has a silent performance hit, or you get an unexpected UnicodeException at runtime due to invalid Unicode. - Jonathan M Davis
