// The purpose of this test is to demonstrate that trait alias expansion // preserves the rule that `dyn Trait` may only reference one non-auto trait. #![feature(trait_alias)] use std::marker::Unpin; // Some arbitrary object-safe traits: trait ObjA {} trait ObjB {} // Nest a few levels deep: trait _0 = ObjA; trait _1 = _0; type _T00 = dyn _0 + ObjB; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T01 = dyn ObjB + _0; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T02 = dyn ObjB + _1; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T03 = dyn _1 + ObjB; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] // Nest some more and in weird ways: trait _2 = ObjB; trait _3 = _2; 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 _2 + _4; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T13 = dyn _4 + _2; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] // Include auto traits: trait _5 = Sync + ObjB + Send; type _T20 = dyn _5 + _1; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T21 = dyn _1 + _5; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T22 = dyn _5 + ObjA; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T23 = dyn ObjA + _5; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T24 = dyn Send + _5 + _1 + Sync; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T25 = dyn _1 + Sync + _5 + Send; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T26 = dyn Sync + Send + _5 + ObjA; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T27 = dyn Send + Sync + ObjA + _5; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] // Also nest: trait _6 = _1 + _5; trait _7 = _6; trait _8 = _7; 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] type _T33 = dyn _8; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T34 = dyn _8 + Send; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T35 = dyn Send + _8; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] // Nest some more: trait _9 = _5 + Sync; trait _10 = Unpin + _9; type _T40 = dyn _10 + ObjA; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T41 = dyn ObjA + _10; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T42 = dyn _10 + _1; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T43 = dyn Send + _10 + Sync + ObjA; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T44 = dyn ObjA + _10 + Send + Sync; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] type _T45 = dyn Sync + Send + _10 + _1; //~^ ERROR only auto traits can be used as additional traits in a trait object [E0225] fn main() {}