[evetion]

Towards #371. Scanning the lowered code of all GeometryOps and GeometryOpsCore methods for Core.Box found 9 methods with boxed captured variables (same on Julia 1.10 and 1.13). This fixes 8 of them, in three commits:

• forcexyz reassigned the captured z inside its apply closure, and called GI.is3d on the whole input, which throws a MethodError for a vector of geometries even though the docstring says vectors work. It now checks each point, which is also what the docstring describes. A new test covers the vector case.
• Polygon clipping: the counters in _build_a_list and last_a_idx in the DoubleNaturalTree traversal are now Refs, and the conditionally reassigned multipoly_a in the multipolygon difference/union methods is let-bound, so those now infer a concrete return type.
• reconstruct (GeometryOpsCore): the iteration state is threaded through a Ref. This needs a GeometryOpsCore version bump, since GeometryOps pins =0.1.12.

The 9th, in ThinnedDoubleNaturalTree, is left alone: it's a typed box with no measurable cost, and that method gives wrong results anyway (#528).

Julia 1.13, median, same results (hashes of the output coordinates) before and after:

	before	after
forcexyz, 10k point polygon	941 µs, 30,034 allocs	3.5 µs, 11 allocs
reconstruct, 25 polygons x 201 points	1.18 ms, 50,310 allocs	3.2 µs, 179 allocs
intersection with DoubleNaturalTree, 4000 x 4000 vertices	1.02 ms, 53,537 allocs	0.34 ms, 68 allocs
intersection, default (NestedLoop), 400 x 400	2.20 ms	2.00 ms
difference of two 3 x 200 multipolygons	5.03 ms	4.58 ms
union of two 3 x 200 multipolygons	1.91 ms	1.74 ms

The full test suite gives the same results as main, plus the two new forcexyz tests. CI will hit the stale overlay_ng.jl:303 test that already fails on main (fixed in #520).

🤖 Generated with Claude Code

[asinghvi17]

Thanks, looks awesome! And with the julia 1.12 improvements to allocation elision it should allocate even less than before.

Looks like something small broke in the polygon clipping code, I'm setting a bot on it.