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extern crate proc_macro;
use proc_macro::*;
// This proc macro ignores its input and returns this token stream
//
// impl <«A1»: Comparable> Comparable for («A1»,) {}
//
// where `«`/`»` are invisible delimiters. This was being misparsed in bug
// #128895.
#[proc_macro]
pub fn main(_input: TokenStream) -> TokenStream {
let a1 = TokenTree::Group(
Group::new(
Delimiter::None,
std::iter::once(TokenTree::Ident(Ident::new("A1", Span::call_site()))).collect(),
)
);
vec![
TokenTree::Ident(Ident::new("impl", Span::call_site())),
TokenTree::Punct(Punct::new('<', Spacing::Alone)),
a1.clone(),
TokenTree::Punct(Punct::new(':', Spacing::Alone)),
TokenTree::Ident(Ident::new("Comparable", Span::call_site())),
TokenTree::Punct(Punct::new('>', Spacing::Alone)),
TokenTree::Ident(Ident::new("Comparable", Span::call_site())),
TokenTree::Ident(Ident::new("for", Span::call_site())),
TokenTree::Group(
Group::new(
Delimiter::Parenthesis,
vec![
a1.clone(),
TokenTree::Punct(Punct::new(',', Spacing::Alone)),
].into_iter().collect::<TokenStream>(),
)
),
TokenTree::Group(Group::new(Delimiter::Brace, TokenStream::new())),
].into_iter().collect::<TokenStream>()
}
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