I'm one of the users who originally voted to close it, and I also voted to leave it closed in the reopen queue after the edit. I also posted the longest and most upvoted comment on that question which attempted to explain the problem, so I suppose I should be the one to defend my decisions here.
And...I just voted to reopen it, so that's another thing to explain.
1. Why did I vote to close the original question?
Because it's too broad/unclear what was meant by "mixing" languages.
Since this is one of many questions where it's easy to imagine someone disagreeing with the closure, as Azure is currently doing (thank you for trying to keep the discussion constructive by the way, far too many users take closure personally), I left one of my usual overly long comments on it when I voted to close:
The direct answer to your question is "all of them, but some are harder than others". So when you say "mix with C++ code", are you talking about languages that provide some built-in support for calling C++ functions, or languages where it's possible to call C++ functions given some effort, or languages that can be freely intermixed with C++ the way C can be mixed with C++ or Objective-C? (unfortunately open-ended list questions like this are off-topic here but we can maybe give you a hint if we know what you're after) – Ixrec Mar 25 at 7:59
If it matters, I did not upvote, downvote, or edit the question at any point.
I do not remember which close reason I personally selected. I suspect it was "unclear" but it may have been "too broad".
2. Why did I click "Leave Closed" in the reopen queue?
Those edit(s) essentially added the term "source code" to the title and body of the question. I simply didn't see how that made the question any more clear, since all languages and all forms of compilation and linking involve at least some pieces of source code at some point.
3) But it has upvoted answers! Doesn't that automatically mean it must've been a good question!?
As is often the case with questions that are too broad or unclear, a large portion of the most-upvoted answer is explaining why the question cannot be answered with any degree of certainty. The bullet point list of languages may give the initial impression that it's directly answering the question, but the text immediately under that list is pretty similar to my comment:
It should be noted that some of these languages are interpreted languages (like R) or a complete platform (like CUDA), and just because it supports you using C++ code does not mean that it will support the C++ standard library (or even strictly adhere to the C++ standard itself), so more investigation would need to be done for those instances.
Depending on what you're trying to provide, using the external C linkage in your C++ might yield a wider array of other langauges to interact with.
4) What about the other >15 edits its had since then?
Honestly, I was completely unaware of them until I started writing this answer. In fact...the explicit contrast between "hybrid compilation" and "scripting and DLL calling solutions" in edit 19 is really good at clarifying the intended scope , so...I just voted to reopen it.
Good call posting a meta thread. I probably never would've seen this edit otherwise.
As a slight tangent: I believe there is an open question as to whether "language identification" questions are categorically off-topic or not, since (as far as I know) we never actually decided as a community that they should be off-topic, but many of us seem to have simply assumed they all fall under the usual "list question" or "nothing to do with software development" or "language recommendation" reasons. But list questions are fine if reasonably scoped to ensure they're not infinite, and we already allow many topics like licensing that seem to have even less to do with software development than language id questions do, and this is not a recommendation question but an identification one. That is why I left those arguments out of the above discussion; I simply don't believe they can be applied to this question in good faith to this particular question (at least not without an explicit meta thread showing that one of my interpretations is off).
