syntax_data: {"ast_node_type":"other","tokens":[{"end":40,"kind":"keyword","start":0,"text":"pub"}]}
source_snippet:     pub closure_sig_as_fn_ptr_ty: I::Ty,
context_before:     /// thus has a peculiar signature of `extern "rust-call" fn((Args, ...)) -> Ty`.
context_after:     /// The upvars captured by the closure. Remains an inference variable