What does “core language” mean?

Question

In the table on this page from the GCC documentation, one of the items (about halfway down the table) is listed as \"core language\" only. What does that mean? What parts of

Answer 1

People often mean everything of C++ except the standard library, which is also part of the language specification.

As an more authoritative example Stephan T. Lavavej (STL) is a key C++ developer at Microsoft. In his lecture series about the Core Language he defines it to be anything you have access to without including any header.

He does not consider himself a Core Language developer. For example he worked on shared_ptr which is a fundamental part of C++11, arguably more fundamental than the strings and streams the comments mention.

The C++ standard does not mention Core Language, but the standard library is

17 Library introduction
18 Language support library
19 Diagnostics library
20 General utilities library
21 Strings library
22 Localization library
23 Containers library
24 Iterators library
25 Algorithms library
26 Numerics library
27 Input/output library
28 Regular expressions library
29 Atomic operations library
30 Thread support library

I would argue chapter 1-16 is (almost?) only concerned with the core language, but there may be more.