error[E0119]: conflicting implementations of trait `Trait1` for type `(dyn std::marker::Send + 'static)` --> $DIR/issue-33140-hack-boundaries.rs:18:1 | LL | impl Trait1 for dyn Send {} | ------------------------ first implementation here LL | impl Trait1 for dyn Send {} | ^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `(dyn std::marker::Send + 'static)` error[E0751]: found both positive and negative implementation of trait `Trait2` for type `(dyn std::marker::Send + 'static)`: --> $DIR/issue-33140-hack-boundaries.rs:25:1 | LL | impl Trait2 for dyn Send {} | ------------------------ positive implementation here LL | impl !Trait2 for dyn Send {} | ^^^^^^^^^^^^^^^^^^^^^^^^^ negative implementation here error[E0119]: conflicting implementations of trait `Trait3<(dyn std::marker::Sync + 'static)>` for type `(dyn std::marker::Send + 'static)` --> $DIR/issue-33140-hack-boundaries.rs:32:1 | LL | impl Trait3 for dyn Send {} | ---------------------------------- first implementation here LL | impl Trait3 for dyn Send {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `(dyn std::marker::Send + 'static)` error[E0119]: conflicting implementations of trait `Trait4a` for type `(dyn std::marker::Send + 'static)` --> $DIR/issue-33140-hack-boundaries.rs:39:1 | LL | impl Trait4a for T {} | ----------------------------- first implementation here LL | impl Trait4a for dyn Send {} | ^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `(dyn std::marker::Send + 'static)` error[E0119]: conflicting implementations of trait `Trait4b` for type `()` --> $DIR/issue-33140-hack-boundaries.rs:46:1 | LL | impl Trait4b for () {} | ------------------- first implementation here LL | impl Trait4b for () {} | ^^^^^^^^^^^^^^^^^^^ conflicting implementation for `()` error[E0119]: conflicting implementations of trait `Trait4c` for type `(dyn Trait1 + std::marker::Send + 'static)` --> $DIR/issue-33140-hack-boundaries.rs:53:1 | LL | impl Trait4c for dyn Trait1 + Send {} | ---------------------------------- first implementation here LL | impl Trait4c for dyn Trait1 + Send {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `(dyn Trait1 + std::marker::Send + 'static)` error[E0119]: conflicting implementations of trait `Trait4d` for type `dyn std::marker::Send` --> $DIR/issue-33140-hack-boundaries.rs:60:1 | LL | impl<'a> Trait4d for dyn Send + 'a {} | ---------------------------------- first implementation here LL | impl<'a> Trait4d for dyn Send + 'a {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `dyn std::marker::Send` error[E0119]: conflicting implementations of trait `Trait5` for type `(dyn std::marker::Send + 'static)` --> $DIR/issue-33140-hack-boundaries.rs:67:1 | LL | impl Trait5 for dyn Send {} | ------------------------ first implementation here LL | impl Trait5 for dyn Send where u32: Copy {} | ^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `(dyn std::marker::Send + 'static)` error: aborting due to 8 previous errors Some errors have detailed explanations: E0119, E0751. For more information about an error, try `rustc --explain E0119`.