Good start but -- some C++ stuff is wrong, e.g. in the bit on friend functions, a member function prototype is written with an empty block instead of a terminal

Good start but -- some C++ stuff is wrong, e.g. in the bit on friend functions, a member function prototype is written with an empty block instead of a terminal ";". Subtle, but you know. Also, more subjectively, std::string is described as immutable, but with no further discussion about what that means or how that might work. Just sayin. Frankly I like how it's not Wikipedianishly drowning in citations and/or demands for same -- but how does it get updated? I immediately tried to expand on those two issues I mentioned but there was no sort of UX recourse for my pedantic urges (FWIW)