|  | //@ revisions: ed2015 ed2021 | 
|  | //@[ed2015] edition: 2015 | 
|  | //@[ed2021] edition: 2021 | 
|  | pub use _::{a, b}; | 
|  | //~^ ERROR expected identifier, found reserved identifier `_` | 
|  | pub use std::{a, _}; | 
|  | //~^ ERROR expected identifier, found reserved identifier `_` | 
|  | //~| ERROR unresolved import `std::a` | 
|  | pub use std::{b, _, c}; | 
|  | //~^ ERROR expected identifier, found reserved identifier `_` | 
|  | //~| ERROR unresolved imports `std::b`, `std::c` | 
|  | pub use std::{_, d}; | 
|  | //~^ ERROR expected identifier, found reserved identifier `_` | 
|  | //~| ERROR unresolved import `std::d` | 
|  |  | 
|  | fn main() {} |