Generic geometric types

[ickshonpe]

What problem does this solve or what need does it fill?

We used to have generic Size and Rect types, but they were specialized (for good reasons IMO).

But it's left some ergonomic friction, especially with measures which take separate width and height Option<f32> and AvailableSpace values which be much cleaner with a generic size type that has map and zip methods like Taffy's Size type .

Also, it would be nice to have some sort of GenericSize<Physical> and GenericSize<Logical> for dealing with window resolutions and scalings.

What solution would you like?

Size could be renamed to UiSize and then name the new generic type Size. UiSize is a bit ugly though.

Otherwise, none of the alternative names I came up with like Dimensions, Extent, Measurements, etc seem super intuitive.

Maybe just Size2 would be okay?

[nicoburns]

I think we could probably get rid of the existing Size type entirely, and just flatten the properties using into directly into Style. So instead of:

• size, min_size, max_size, and gap properties

We'd have:

• width, height, min_width, min_height, max_width, max_height, row_gap, and column_gap properties

IMO that would be an ergonomic improvement from an end-user perspective.

UPDATE: Implemented in #8548