I have certainly been confused by the term 'tuple' used in D countless times.
It seems to exist in a variety of different contexts, and every time I think I understood it, I realise I'm probably wrong some time later.
There seems to be poor/no documentation comparing/distinguishing various D tuples, also, there seems to be no real explicit syntax, which makes it hard to recognise.
I can kinda handle a Tuple template, and then there are these type tuples, and then expression tuples? What is the relationship between these? Are they compatible? How do I distinguish them?
Someone that understand what they're talking about should take some time to write a comprehensive article on the matter :)
Some of the things I have read seem to presume that I already know what it's talking about, and as a result, lead to dismissing or misunderstanding the article.
I think the practical take-away from my experience is that it ends up as one of those 'too hard' concepts, that I develop a tendency to actively avoid dealing with because it's confused me a number of times.
I typically just start typing stuff and hope it works. And if it doesn't I fiddle with it until it eventually does (or I give up), and I never *really* understand why.
I'll bet I'm not the only one...