Precision system

[chenkasirer]

Related to: #1057 (comment)

Some kind of a precision system can be useful which allows user to:

• get/set a globally desired unit (mm/meter/cm etc.)
• get/set a local version of the above
• get/set the desired tolerance for each

This would replace all sorts of local tolerance which aren't standardized and are defined per module/class/instance.
Maybe in form of a Precision mixin which will by default fetch values from a global default and allow setting a modified local copy thereof.

[gonzalocasas]

I always felt we needed to add built-in/native support for units across the board. Something like what astropy does: https://docs.astropy.org/en/stable/units/index.html

Because, well, it's important :)

[jf---]

@tomvanmele I think this can be closed with the Precision class being added in 2.0

[yck011522]

@jf--- as far as I understand, the new Precision class solves the tolerance problem but did not really solve the lack of units problem that @gonzalocasas mentioned.

[jf---]

Gotcha, thanks for pointing out. But that seems another issue altogether: precision and metric(s) and 2 separate issues of concern.

[gonzalocasas]

Closing this and opened #1319 for the units idea/discussion