Say I have minimal headers like <new>, <initializer_list>, and maybe some other stuff, is it possible to use Boost to function as a std C++ library, or is there a lot of code missing?
I’m assuming a C standard library, which might have sucky versions of things like printf (think Windows), will Boost provide better implementations in <boost/cstddef> (or something)?
No. Boost is not designed to replace the C++ standard library; it is designed to complement and extend the C++ standard library. Also, Boost depends heavily on the C++ standard library.