Is it possible to implement something like puts/printf/cout/etc using only the keywords that C/C++ offer? ie, can you print something to the console without depending on any external libraries?
Notice that printf, cout etc are not part of 'external libraries', they are part of the standard library which is part of C++.
To print stuff just with a programming language you should use assembly or try the C++ keyword for assembly code:
asm ( "Some assembly code here ( the language depends on the compiler ) " );