This implements the initial version of the std::formatter class and its
specializations. It also implements the following formatting functions:
All functions have a char and wchar_t version. The locale overloaded
versions aren't implemented yet. Parsing the format-spec and using the
parsed format-spec hasn't been implemented. The code isn't optimized,
neither for speed, nor for size.
The goal is to have the rudimentary basics working, which can be used as a
basis to improve upon.
Implements parts of:
- P0645 Text Formatting
Depends on D93593