id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
30889	gis.measure: Distance/Distance should error.	Robert Coup	nobody	"The original design principle of the measure module were to:
1. minimise unit mismatching errors
2. avoid bad maths on units.
3. provide helpful converters so everyone doesn't have constants all over their codebases

With respect to (2), for example: (Area * Distance) is a meaningless thing - m³

While `Distance / Distance`  (& `Area / Area`) do produce ratios, they are ''quite likely'' to be an error.

Originally `Distance / Distance` would raise a `TypeError`, same as `Area / Area` still does currently. This was changed during a refactoring a while back (#17754).

Suggestion to resolve:

1. Add a `MeasureBase.ratio(other)` method, which makes it really explicit what is happening
2. Make `Distance / Distance` raises a `DeprecationWarning`, and eventually go back to raising a `TypeError`
3. ~~Alias `ratio()` to another operator (eg. `%`)~~ I think it's not used enough to actually be clearly readable to anyone."	New feature	closed	GIS	dev	Normal	wontfix		Claude Paroz	Unreviewed	0	0	0	0	0	0