src/test/ui/dyn-keyword/dyn-2015-idents-in-macros-unlinted.rs

   1 // Under the 2015 edition with the keyword_idents lint, `dyn` is
   2 // not entirely acceptable as an identifier.
   3 //
   4 // We currently do not attempt to detect or fix uses of `dyn` as an
   5 // identifier under a macro.
   6 //
   7 // check-pass
   8 // edition:2015
   9
  10 #![allow(non_camel_case_types)]
  11 #![deny(keyword_idents)]
  12
  13 mod outer_mod {
  14     pub mod r#dyn {
  15         pub struct r#dyn;
  16     }
  17 }
  18
  19 // Here we are illustrating that the current lint does not flag the
  20 // occurrences of `dyn` in this macro definition; however, it
  21 // certainly *could* (and it would be nice if it did), since these
  22 // occurrences are not compatible with the 2018 edition's
  23 // interpretation of `dyn` as a keyword.
  24 macro_rules! defn_has_dyn_idents {
  25     () => { ::outer_mod::dyn::dyn }
  26 }
  27
  28 struct X;
  29 trait Trait { fn hello(&self) { }}
  30 impl Trait for X { }
  31
  32 macro_rules! tt_trait {
  33     ($arg:tt) => { & $arg Trait }
  34 }
  35
  36 macro_rules! id_trait {
  37     ($id:ident) => { & $id Trait }
  38 }
  39
  40 fn main() {
  41     defn_has_dyn_idents!();
  42
  43     // Here we are illustrating that the current lint does not flag
  44     // the occurrences of `dyn` in these macro invocations. It
  45     // definitely should *not* flag the one in `tt_trait`, since that
  46     // is expanding in a valid fashion to `&dyn Trait`.
  47     //
  48     // It is arguable whether it would be valid to flag the occurrence
  49     // in `id_trait`, since that macro specifies that it takes an
  50     // `ident` as its input.
  51     fn f_tt(x: &X) -> tt_trait!(dyn) { x }
  52     fn f_id(x: &X) -> id_trait!(dyn) { x }
  53
  54     let x = X;
  55     f_tt(&x).hello();
  56     f_id(&x).hello();
  57 }