LO calc formulas

[Stephan Bergmann]

On 11/12/2020 21:41, Dante Doménech wrote:
> I've been digging into calc code. And it makes me wonder about a few things.
> First, in here: core 
> <https://opengrok.libreoffice.org/xref/core/>/include 
> <https://opengrok.libreoffice.org/xref/core/include/>/rtl 
> <https://opengrok.libreoffice.org/xref/core/include/rtl/>/math.hxx 
> <https://opengrok.libreoffice.org/xref/core/include/rtl/math.hxx>
> We have our own isnan, isinf, isfinite, ... and some of them with quite 
> strange code.
> Why is the default c++ standard library isn't good enough?
> The same goes for floor / ceil / round ...

Those include files that are part of the stable URE interface(*) have 
rather picky requirements.  They are meant to be included by rather old 
(pre-C99, pre-C++11) compilers, and changes to their content likely 
cause incompatible changes to the stable URE interface.  I would avoid 
modifications of those files without a clear need and without a solid 
understanding of the implications.

* For a list of all the C/C++ include files that make up the stable URE 
interface see workdir/CustomTarget/odk/allheaders/allheaders.hxx 
generated by `make CustomTarget_odk/allheaders`.