16 Library introduction [library]

The C++ standard library provides the following C++ library modules.

The named module std exports declarations in namespace std that are provided by the importable C++ library headers (Table Clause 24 or the subset provided by a freestanding implementation) and the C++ headers for C library facilities (Table Clause 25).

It additionally exports declarations in the global namespace for the storage allocation and deallocation functions that are provided by <new>.

The named module std.compat exports the same declarations as the named module std, and additionally exports

• (3.1)
  declarations in the global namespace corresponding to the declarations in namespace std that are provided by the C++ headers for C library facilities (Table Clause 25), except the explicitly excluded declarations described in [support.c.headers.other] and
• (3.2)
  declarations provided by the headers <stdbit.h> and <stdckdint.h>.

It is unspecified to which module a declaration in the standard library is attached.

Recommended practice: Implementations should ensure such attachments do not preclude further evolution or decomposition of the standard library modules.

A declaration in the standard library denotes the same entity regardless of whether it was made reachable through including a header, importing a header unit, or importing a C++ library module.

Recommended practice: Implementations should avoid exporting any other declarations from the C++ library modules.