- Update to 0.18.1:
* fixed a 32-bit Linux build issue as discovered on Debian, due to a clash on
two 32-bit unsigned integer types being used with std::variant.
- Update to 0.18.0:
* removed the formula_model_access interface from model_context, and switched
to using model_context directly everywhere.
* revised formula_tokens_t type to remove use of std::unique_ptr for each
formula_token instance. This should improve memory locality when
iterating through an array of formula token values. A similar change has
also been made to lexer_tokens_t and lexer_token types.
* added 41 built-in functions
* added support for multi-sheet references in Excel A1 and Excel R1C1
grammers.