mirror of https://github.com/rust-lang/rust
21 lines
582 B
Rust
21 lines
582 B
Rust
//@ force-host
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//@ no-prefer-dynamic
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#![crate_type = "proc-macro"]
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extern crate proc_macro;
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use proc_macro::{TokenStream, TokenTree, Group, Delimiter};
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#[proc_macro_attribute]
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pub fn first(_attr: TokenStream, item: TokenStream) -> TokenStream {
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let tokens: TokenStream = "#[derive(Second)]".parse().unwrap();
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let wrapped = TokenTree::Group(Group::new(Delimiter::None, item.into_iter().collect()));
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tokens.into_iter().chain(std::iter::once(wrapped)).collect()
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}
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#[proc_macro_derive(Second)]
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pub fn second(item: TokenStream) -> TokenStream {
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TokenStream::new()
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}
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