|  | warning: use of a double negation | 
|  | --> $DIR/lint-double-negations-macro.rs:9:9 | 
|  | | | 
|  | LL |         --$e | 
|  | |         ^^^^ | 
|  | ... | 
|  | LL |     bad_macro!(1); | 
|  | |     ------------- in this macro invocation | 
|  | | | 
|  | = note: the prefix `--` could be misinterpreted as a decrement operator which exists in other languages | 
|  | = note: use `-= 1` if you meant to decrement the value | 
|  | = note: `#[warn(double_negations)]` on by default | 
|  | = note: this warning originates in the macro `bad_macro` (in Nightly builds, run with -Z macro-backtrace for more info) | 
|  | help: add parentheses for clarity | 
|  | | | 
|  | LL |         -(-$e) | 
|  | |          +   + | 
|  |  | 
|  | warning: 1 warning emitted | 
|  |  |