Судя по последним сообщениям на форуме, C++ в ядре Windows уже не редкость.
Если кто-то пропустил, Microsoft анонсировала часть STL для использования в ядре:

The header structure of the STL was changed to allow use of a subset of the library in conditions where the user can’t link with msvcp140.dll, such as driver development. (Previously the hard dependency on msvcp and pragma detect mismatch were injected by our base configuration header included by everything.) The following headers are now considered “core” and don’t inject our runtime dependencies (though we do still assume some form of CRT headers are present):

• <cstddef>
  
• <cstdlib>
  
• <initializer_list>
  
• <ratio>
  
• <type_traits>

We aren’t actually driver developers ourselves and are interested in feedback in this area if there are things we can do to make these more usable in constrained environments.

Это, конечно, не shared_ptr, но уже хоть что-то.