// The purpose of this test is to demonstrate that duplicating object safe traits // that are not auto traits is rejected with trait aliases even though one could // reasonably accept this. #![feature(trait_alias)] use std::marker::Unpin; // Some arbitrary object-safe trait: trait Obj {} // Nest a few levels deep: trait _0 = Obj; trait _1 = _0; type _T00 = dyn _0 + _0; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T01 = dyn _1 + _0; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T02 = dyn _1 + _1; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T03 = dyn Obj + _1; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T04 = dyn _1 + Obj; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] // Nest some more and in weird ways: trait _2 = _0 + _1; trait _3 = Obj; trait _4 = _3; type _T10 = dyn _2 + _3; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T11 = dyn _3 + _2; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T12 = dyn Obj + _2; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T13 = dyn _2 + Obj; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T14 = dyn _1 + _3; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T15 = dyn _3 + _1; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T16 = dyn _1 + _4; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T17 = dyn _4 + _1; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] // Include auto traits: trait _5 = Obj + Send; type _T20 = dyn _5 + _5; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T21 = dyn Obj + _5; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T22 = dyn _5 + Obj; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T23 = dyn _5 + Send + Sync + Obj; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] // Also nest: trait _6 = _5 + _5; // ==> Obj + Send + Obj + Send type _T30 = dyn _6; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T31 = dyn _6 + Send; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T32 = dyn Send + _6; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] // Nest some more: trait _7 = _5 + Sync; trait _8 = Unpin + _7; type _T40 = dyn _8 + Obj; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T41 = dyn Obj + _8; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T42 = dyn _8 + _4; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T43 = dyn _4 + _8; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T44 = dyn _4 + Send + Sync + _8; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] // Take higher ranked types into account. // Note that `'a` and `'b` are intentionally different to make sure we consider // them semantically the same. trait ObjL<'l> {} trait _9 = for<'a> ObjL<'a>; trait _10 = for<'b> ObjL<'b>; type _T50 = dyn _9 + _10; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] trait ObjT {} trait _11 = ObjT fn(&'a u8)>; trait _12 = ObjT fn(&'b u8)>; type _T60 = dyn _11 + _12; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] fn main() {}