Hygiene breaks add_one! macro

[dtolnay]

The add_one! example from the readme works with nightly-2017-12-02 but not nightly-2017-12-03.

   Compiling example v0.0.0
error[E0425]: cannot find value `x` in this scope
 --> src/main.rs:8:16
  |
8 |     let nine = add_one!(x) + add_one!(2 + 3);
  |                ^^^^^^^^^^^ not found in this scope
  |

[rushmorem]

Is there a workaround for this?

[tcr]

@rushmorem No workaround exists. As a result of rust-lang/rust#46478 it was decided that the fix for macro hygiene will stay, disallowing the use of local variables as macro input to proc-macro-hack.

As of 727987f add_one() in the README no longer references local variables anymore.

[dtolnay]

Fixed in 0.5.0.