// Demonstrates and records a theoretical regressions / breaking changes caused by the // introduction of `const` and `[const]` trait bounds. // Setting the edition to >2015 since we didn't regress `demo! { dyn const }` in Rust 2015. // See also test `traits/const-traits/macro-dyn-const-2015.rs`. //@ edition:2018 trait Trait {} macro_rules! demo { ($ty:ty) => { compile_error!("ty"); }; // KEEP THIS RULE FIRST AND AS IS! //~^ ERROR ty //~| ERROR ty //~| ERROR ty //~| ERROR ty // DON'T MODIFY THE MATCHERS BELOW UNLESS THE CONST TRAIT MODIFIER SYNTAX CHANGES! (impl $c:ident Trait) => { /* KEEP THIS EMPTY! */ }; (dyn $c:ident Trait) => { /* KEEP THIS EMPTY! */ }; (impl [const] Trait) => { /* KEEP THIS EMPTY! */ }; (dyn [const] Trait) => { /* KEEP THIS EMPTY! */ }; } demo! { impl const Trait } //~ ERROR const trait impls are experimental demo! { dyn const Trait } //~ ERROR const trait impls are experimental demo! { impl [const] Trait } //~ ERROR const trait impls are experimental demo! { dyn [const] Trait } //~ ERROR const trait impls are experimental fn main() {}