syntax_data: {"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":"//!"}]}
source_snippet: //! - `as_temp` -> creates a temporary and either calls `as_place` or `into`
context_before: //! - `as_constant` -> (no fallback)
context_after: //! - `as_place` -> for rvalues, falls back to `as_temp` and returns that