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use proc_macro2::{Group, Span, TokenStream, TokenTree}; pub(crate) fn respan(stream: TokenStream, span: Span) -> TokenStream { stream .into_iter() .map(|token| respan_token(token, span)) .collect() } fn respan_token(mut token: TokenTree, span: Span) -> TokenTree { if let TokenTree::Group(g) = &mut token { *g = Group::new(g.delimiter(), respan(g.stream(), span)); } token.set_span(span); token }