I usually try to get away with reading as little of the manual as possible until I absolutely have to. Articles like this really help cavemen like me because this is leaps and bounds better than reading the actual c++ standard!
C++ is really the one language where I suggest reading the manual, repeatedly. Sometimes I go and read the docs at cppreference for practically every expression I write.
I'd say it's rather an attempt at having some kind of actual user manual. It's not going to be as precise (or authoritive) as the standard, but instead the focus is on being more digestible for users.
cppreference.com is by far the best resource for the language and the standard library. It is also well organized and easy to navigate. "errors creep in" is a well-taken complaint about life in general, not cppreference.
I implemented a printf format checker for D, which checks that the argument types are compatible with the format specifiers. (This is really a nice feature, I should have done it long ago.)
To be successful, it had to correctly deal with every nuance of the printf spec. cppreference got a couple of these incorrect wrt to modifiers. Not something a routine user would notice, but a pedantic one would. (Sorry, I don't remember exactly what the mistakes were.)
I still use cppreference because it is so dang convenient. But I don't rely on it when perfection is required.
It's really too bad that copyright forces everyone writing a manual to rewrite & rephrase things. I wish the C++ Standard was online.
One online reference I dearly like is https://www.felixcloutier.com/x86/index.html which has saved me so much time. But it was created by scanning the actual reference manuals, so barring scanning errors, it is exactly correct. I gave up using reformulations of the CPU instruction set long ago, they had too many mistakes.
You might be interested in the EXEgesis project, which is also a machine interpretation of x86 documentation, but which includes several patches for unfixed errata therein.
