syntax_data: {"ast_node_type":"other","tokens":[{"end":48,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// `expr` is a valid compile-time constant!
context_before:     /// Compile `expr`, yielding a compile-time constant. Assumes that
context_after:     pub(crate) fn as_constant(&mut self, expr: &Expr<'tcx>) -> ConstOperand<'tcx> {