really finds the maximum common ration as opposed to previous algo which
simplified on the exp part of the ratio by using std::min
most of new code credit to Conor Williams
discussion and additional doc here:
https://github.com/mpusz/units/issues/62#issuecomment-588152833
test case was 1yd + 1in = 37in => added as a test
commenting out unusued ratio_add and its tests
if to be reintroduced, should also use the new gcd routines
additonal change was required to check in `safe_divisible` concept
den=1 is not sufficient anymore. reusing new gcd routines
moved ratio nomalize and new gcd routines into new, separate bits/ratio_maths.h
this resolves#62
new namespaces are
international ( combination of us and imperial + Canada etc)
iau (https://www.iau.org/
imperial ( old imperial units)
typographical ( for sizes of printing fonts etc)
These namespace are based on some research , mainly on wikipedia.
Look in src/include/units/physical/si/length.h to see links to see the references to documentation justifying the change.
Unfortunately there are 3 foot units for example, an old imperial version, an old us version and an international version, which is more recent and attempts to unify the two previous ones. All versions have slight changes in value, so I opted to use the international version
The main change in the layout is that inch,foot and yard have been moved from us to international.
With this modification, I also modified the physical/us/area.hpp, volume.hpp and volume.hpp headers to refer to the international units.
This may not be correct, but if the modified us::foot (rather than international foot is used as a basis for these units, then
there is a ratio integer overflow during compilation, probably due to taking 3rd power of a ratio. After this commit. I will try to show that on another branch.
Mateusz Pusz
Mike Ford
Ramzi Sabra
rbrugo
Oliver Schönrock
Andy Little