Struct MultiArrangement 

pub struct MultiArrangement {
    pub interner: Interner,
    pub subtris: Vec<Vec<[Vid; 3]>>,
    pub unrecovered: usize,
}

The conforming arrangement of n operand meshes over one shared interner. subtris[k] is mesh k’s conforming sub-triangles; there is no separate owner/index table — a sub-triangle’s originating mesh is simply its position k in subtris.

Fields

interner: Interner

subtris: Vec<Vec<[Vid; 3]>>

subtris[k] = mesh k’s conforming sub-triangles (interned Vids).

unrecovered: usize

Total constraint sub-segments the per-mesh re-triangulations could not force as edges (summed over every mesh’s Mesh2d::unrecovered). Non-zero ⇒ the operands do not fully conform along their intersections, so a straddling sub-triangle’s centroid classification in union_all is unreliable (the union can silently tear). Mirrors Arrangement::unrecovered so union_all can SIGNAL the same non-conformity condition difference_all hard-rejects (it was previously discarded into a _).