syntax_data: {"ast_node_type":"other","tokens":[{"end":100,"kind":"keyword","start":0,"text":"unpack!(block"}]}
source_snippet:                     unpack!(block = this.expr_as_place(block, arg, mutability, fake_borrow_temps,));
context_before:                 let place_builder =
context_after:                 block.and(place_builder.deref())