[GH#365] Add select_most_precise<T1, T2> to properly type results of arithmetic operations

From: Mateusz Loskot (mateusz_at_[hidden])
Date: 2019-08-01 16:11:12

Hi,

Following some discussion with Olzhas about choosing types for
results of arithmetic operations, and some older issues pointed
out by Samuel Debionne ago, I opened an issue/task to discuss
proposal of possible solution borrowed from Boost.Geometry,
which also heavily relies on correctness of arithmetic operations
based on mixed types of operands.

https://github.com/boostorg/gil/issues/363

Any feedback is welcome! Here or as the issue comments.
Help in implementing the solution will be highly appreciated too :)

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net