The Difference Between Core And Non Core Headers

In our implementation, you'll see that some headers are annotated:

// example standard header (core)

while others are only:

// example standard header

without a (core) suffix. "core" refers to headers that can be #include'd into translation units without generating import declarations forcing linking with the standard libraries. The intent is to enable use of such headers in constrained operating environments like:

• the STL's own import libraries (where we merge functionality into the DLL's import lib to avoid needing to create a new DLL for some piece of functionality)
• kernel code
• Windows code that can't link with the STL
• enclave / SGX protected code

Generally, we want "compiler support" headers like <type_traits> to be in the core subset so that even constrained environments can get the "core speaking through std::" features. Core headers all start with #include <yvals_core.h> or another header that does so; other headers generally start with #include <yvals.h>.