It would be nice to have an alternate design to investigate or a list of problems with singleton equality to resolve. Otherwise there's little to be done with this issue.

Yeah, this is just something that I want to give some thought to, so I wanted a bug to track it.

Note to self: this is also why the destructor for InterpolationType is ASSERT_NOT_REACHED()

InterpolationType comparison is a crucial part of registered custom property support, so any work here will need to be careful of that.

I'm not likely to work on this soon, so making it Available. I'm actively working on the broader Objective (issue 654309), however, and happy to brief someone if they want to take it up before I get back to it.

Would you be able to document the brief here? I'm not convinced this is actually an issue.

My intuition is that the design is fragile, but I can't put my finger on why. I think some part of my brain is rebelling at the notion of having an object to represent a type, when types are more like classes. Maybe it's a naming issue in disguise, or maybe it's a sign that the design of this code is off-kilter. I find the concept of the design somewhat difficult to grasp, and hence I think something here falls under the "Simplify interpolation code in Blink" Objective. It troubles me that I can't see what might be needed, and at this stage am hoping that other simplification work will start to make it clearer.

A design closer to AnimatableValues would probably resolve your unease.
I imagine one path could be to push InterpolableValues and InterpolationTypes into NonInterpolableValues. NIVs already have the ability to know when two objects are of different subclasses (see the virtual getType() method), that could be used in place of InterpolationType's operator==() pointer comparison.

This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

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