src/doc/book/listings/ch19-advanced-features/listing-19-31/hello_macro/hello_macro_derive/src/lib.rs

   1 extern crate proc_macro;
   2
   3 use proc_macro::TokenStream;
   4 use quote::quote;
   5 use syn;
   6
   7 #[proc_macro_derive(HelloMacro)]
   8 pub fn hello_macro_derive(input: TokenStream) -> TokenStream {
   9     // Construct a representation of Rust code as a syntax tree
  10     // that we can manipulate
  11     let ast = syn::parse(input).unwrap();
  12
  13     // Build the trait implementation
  14     impl_hello_macro(&ast)
  15 }