mirror of
https://github.com/rust-lang/rust
synced 2024-09-15 22:50:55 +00:00
6dbad23641
```
error[E0277]: the trait bound `S: d::Hidden` is not satisfied
--> $DIR/sealed-trait-local.rs:53:20
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LL | impl c::Sealed for S {}
| ^ the trait `d::Hidden` is not implemented for `S`
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note: required by a bound in `c::Sealed`
--> $DIR/sealed-trait-local.rs:17:23
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LL | pub trait Sealed: self::d::Hidden {
| ^^^^^^^^^^^^^^^ required by this bound in `Sealed`
= note: `Sealed` is a "sealed trait", because to implement it you also need to implement `c::d::Hidden`, which is not accessible; this is usually done to force you to use one of the provided types that already implement it
= help: the following types implement the trait:
- c::X
- c::Y
```
The last `help` is new.
56 lines
972 B
Rust
56 lines
972 B
Rust
// provide custom privacy error for sealed traits
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pub mod a {
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pub trait Sealed: self::b::Hidden {
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fn foo() {}
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}
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struct X;
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impl Sealed for X {}
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impl self::b::Hidden for X {}
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mod b {
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pub trait Hidden {}
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}
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}
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pub mod c {
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pub trait Sealed: self::d::Hidden {
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fn foo() {}
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}
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struct X;
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impl Sealed for X {}
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impl self::d::Hidden for X {}
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struct Y;
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impl Sealed for Y {}
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impl self::d::Hidden for Y {}
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mod d {
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pub trait Hidden {}
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}
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}
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pub mod e {
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pub trait Sealed: self::f::Hidden {
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fn foo() {}
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}
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struct X;
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impl self::f::Hidden for X {}
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struct Y;
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impl self::f::Hidden for Y {}
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impl<T: self::f::Hidden> Sealed for T {}
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mod f {
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pub trait Hidden {}
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}
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}
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struct S;
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impl a::Sealed for S {} //~ ERROR the trait bound
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impl c::Sealed for S {} //~ ERROR the trait bound
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impl e::Sealed for S {} //~ ERROR the trait bound
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fn main() {}
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