Module embed_enum_variant_patch 

stmt::patch may step through embedded structs and may replace an embedded enum as a whole, but it may not enter an enum variant. These tests pin that boundary: a path into a variant rejects the whole update with unsupported_feature before any write, while the supported forms on the same model keep working.

Functions

patch_beside_variant_boundary

The supported forms on the same model: patching a struct field beside the enum, and replacing an enum nested in the struct as a whole.

reject_increment_through_variant

reject_patch_through_nested_variants

reject_set_through_variant