The fact that you’ve named an IDE vendor rather emphasises that there is a substantial gray area. By no means everyone wants to use an IDE (let alone that specific one...)
True. But for Objective-C I often used the NY Times style guide. Just whatever the one is that is the most complete and most easy to maintain really. But I notice with C# that if I copy-paste reasonably fresh code from Stack Overflow to VS + RS I sometimes get zero warnings because the other programmer uses exactly the same toolchain and style. Same goes for Python PEP8 in PyCharm. Personally I like the idea of having a strong similarity in code style within an ecosystem, especially when dealing with libraries that more or less follow the same conventions as the code that I wrote myself.