f78f93bc9f
This is the first step to implement time zone support in libc++. This adds the complete tzdb_list class and a minimal tzdb class. The tzdb class only contains the version, which is used by reload_tzdb. Next to these classes it contains documentation and build system support needed for time zone support. The code depends on the IANA Time Zone Database, which should be available on the platform used or provided by the libc++ vendors. The code is labeled as experimental since there will be ABI breaks during development; the tzdb class needs to have the standard headers. Implements parts of: - P0355 Extending <chrono> to Calendars and Time Zones Addresses: - LWG3319 Properly reference specification of IANA time zone database Reviewed By: #libc, ldionne Differential Revision: https://reviews.llvm.org/D154282
The "module partitions" for the std module
The files in this directory contain the exported named declarations per header. These files are used for the following purposes:
- During testing exported named declarations are tested against the named declarations in the associated header. This excludes reserved names; they are not exported.
- Generate the module std.
These use cases require including the required headers for these "partitions" at different locations. This means the user of these "partitions" are responsible for including the proper header and validating whether the header can be loaded in the current libc++ configuration. For example "include " fails when locales are not available. The "partitions" use the libc++ feature macros to export the declarations available in the current configuration. This configuration is available if the user includes the `__config' header.
We use .inc files that we include from the top-level module instead of
using real C++ module partitions. This is a lot faster than module partitions,
see this for details.