This is a common mistification. No actual hardware can "run" C++. 3ds, as any other hardware, can just run machine code instructions. While tools to "translate" C/C++ into 3ds machine code actually exists (the C compiler paired with the devkitpro cross-compiling toolchain) we are lacking ways to translate other languages into 3ds machine code. Of course nothing prevents us to write these translators at all
But i have been ninja'd