mirror of https://github.com/rust-lang/rust
20 lines
692 B
Rust
20 lines
692 B
Rust
/// The compiler previously did not properly check the bound of `From` when it was used from type
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/// of the dyn trait object (use in `copy_any` below). Since the associated type is under user
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/// control in this usage, the compiler could be tricked to believe any type implemented any trait.
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/// This would ICE, except for pure marker traits like `Copy`. It did not require providing an
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/// instance of the dyn trait type, only name said type.
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trait Setup {
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type From: Copy;
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}
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fn copy<U: Setup + ?Sized>(from: &U::From) -> U::From {
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*from
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}
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pub fn copy_any<T>(t: &T) -> T {
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copy::<dyn Setup<From=T>>(t)
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//~^ ERROR the trait bound `T: Copy` is not satisfied
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}
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fn main() {}
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