| extern crate proc_macro; | 
 |  | 
 | use proc_macro::TokenStream; | 
 |  | 
 | #[proc_macro_attribute] | 
 | pub fn expect_let(attr: TokenStream, item: TokenStream) -> TokenStream { | 
 |     assert!(attr.to_string().is_empty()); | 
 |     assert_eq!(item.to_string(), "let string = \"Hello, world!\";"); | 
 |     item | 
 | } | 
 |  | 
 | #[proc_macro_attribute] | 
 | pub fn expect_my_macro_stmt(attr: TokenStream, item: TokenStream) -> TokenStream { | 
 |     assert!(attr.to_string().is_empty()); | 
 |     assert_eq!(item.to_string(), "my_macro! (\"{}\", string);"); | 
 |     item | 
 | } | 
 |  | 
 | #[proc_macro_attribute] | 
 | pub fn expect_expr(attr: TokenStream, item: TokenStream) -> TokenStream { | 
 |     assert!(attr.to_string().is_empty()); | 
 |     assert_eq!(item.to_string(), "print_str(\"string\")"); | 
 |     item | 
 | } | 
 |  | 
 | #[proc_macro_attribute] | 
 | pub fn expect_my_macro_expr(attr: TokenStream, item: TokenStream) -> TokenStream { | 
 |     assert!(attr.to_string().is_empty()); | 
 |     assert_eq!(item.to_string(), "my_macro!(\"{}\", string)"); | 
 |     item | 
 | } | 
 |  | 
 | #[proc_macro_attribute] | 
 | pub fn duplicate(attr: TokenStream, item: TokenStream) -> TokenStream { | 
 |     assert!(attr.to_string().is_empty()); | 
 |     format!("{}, {}", item, item).parse().unwrap() | 
 | } | 
 |  | 
 | #[proc_macro_attribute] | 
 | pub fn no_output(attr: TokenStream, item: TokenStream) -> TokenStream { | 
 |     assert!(attr.to_string().is_empty()); | 
 |     assert!(!item.to_string().is_empty()); | 
 |     "".parse().unwrap() | 
 | } |