mirror of https://github.com/rust-lang/rust
122 lines
3.8 KiB
Rust
122 lines
3.8 KiB
Rust
// The purpose of this test is to demonstrate that trait alias expansion
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// preserves the rule that `dyn Trait` may only reference one non-auto trait.
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#![feature(trait_alias)]
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use std::marker::Unpin;
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// Some arbitrary object-safe traits:
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trait ObjA {}
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trait ObjB {}
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// Nest a few levels deep:
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trait _0 = ObjA;
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trait _1 = _0;
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type _T00 = dyn _0 + ObjB;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T01 = dyn ObjB + _0;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T02 = dyn ObjB + _1;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T03 = dyn _1 + ObjB;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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// Nest some more and in weird ways:
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trait _2 = ObjB;
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trait _3 = _2;
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trait _4 = _3;
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type _T10 = dyn _2 + _3;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T11 = dyn _3 + _2;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T12 = dyn _2 + _4;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T13 = dyn _4 + _2;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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// Include auto traits:
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trait _5 = Sync + ObjB + Send;
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type _T20 = dyn _5 + _1;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T21 = dyn _1 + _5;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T22 = dyn _5 + ObjA;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T23 = dyn ObjA + _5;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T24 = dyn Send + _5 + _1 + Sync;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T25 = dyn _1 + Sync + _5 + Send;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T26 = dyn Sync + Send + _5 + ObjA;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T27 = dyn Send + Sync + ObjA + _5;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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// Also nest:
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trait _6 = _1 + _5;
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trait _7 = _6;
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trait _8 = _7;
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type _T30 = dyn _6;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T31 = dyn _6 + Send;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T32 = dyn Send + _6;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T33 = dyn _8;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T34 = dyn _8 + Send;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T35 = dyn Send + _8;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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// Nest some more:
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trait _9 = _5 + Sync;
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trait _10 = Unpin + _9;
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type _T40 = dyn _10 + ObjA;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T41 = dyn ObjA + _10;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T42 = dyn _10 + _1;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T43 = dyn Send + _10 + Sync + ObjA;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T44 = dyn ObjA + _10 + Send + Sync;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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type _T45 = dyn Sync + Send + _10 + _1;
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//~^ ERROR only auto traits can be used as additional traits in a trait object [E0225]
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fn main() {}
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