Function proc_macro_error::dummy::set_dummy

pub fn set_dummy(dummy: Option<TokenStream>) -> Option<TokenStream>

Sets dummy token stream which will be appended to compile_error!(msg);... invocations, should a trigger happen. Returns an old dummy, if set.

Warning:

If you do set_dummy(Some(ts)) you must do set_dummy(None) before macro execution completes (filer_macro_errors! will do that for you)! Otherwise rustc will fail with creepy

thread 'rustc' panicked at 'use-after-free in `proc_macro` handle', src\libcore\option.rs:1166:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
error: proc-macro derive panicked