Thanks, I can't see the anything there which shows me all of the available things in the std:: namespace? That's just a page of the whole C++ language. I'm trying to ascertain what lives in the std:: namespace.
Pretty much anything that isn't the core language is in the std namespace.
Basically everything defined in header files is in std (except that some stuff, such as the C library, is commonly dumped into the global namespace).
Maybe see a list of all header files: https://en.cppreference.com/w/cpp/header
anything that is a part of the standard library is a part of the std namespace (with some exceptions, like dutch mentioned with certain C library functions). This includes std::vector and std::array, etc.
The fundamental types (int, bool, char) along with keywords are all implemented in the language ITSELF, not through standard library headers. Thus, you don't need to prefix them with std::