Replacing try macro in 2018 edition about rerast HOT 3 OPEN

Thanks for the feedback. The example in the cookbook can be made clearer by switching it to use r#try - then it will work on both 2015 edition and 2018 edition and will match both try! (2015) and r#try! (2015 or 2018). I'll update the cookbook.

from rerast.

Thanks. I did try editing the example to use r#try but it didn't work, but I can see if I do it in a trivial test project it does work. I'll try to reduce my failing case and may come back.

from rerast.

Ok, I've figured out my problem isn't directly related to r#try - I'll add a new issue to cover it.

from rerast.