01e83adc88
but a C-variadic method makes a trait dyn-incompatible. That is because methods from dyn traits, when cast to a function pointer, create a shim. That shim can't really forward the c-variadic arguments.
22 lines
956 B
Plaintext
22 lines
956 B
Plaintext
error[E0038]: the trait `Trait` is not dyn compatible
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--> $DIR/not-dyn-compatible.rs:27:30
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LL | let dyn_object: &dyn Trait = &Struct(64);
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| ^^^^^ `Trait` is not dyn compatible
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note: for a trait to be dyn compatible it needs to allow building a vtable
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for more information, visit <https://doc.rust-lang.org/reference/items/traits.html#dyn-compatibility>
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--> $DIR/not-dyn-compatible.rs:14:26
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LL | trait Trait {
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| ----- this trait is not dyn compatible...
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...
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LL | unsafe extern "C" fn dyn_method_ref(&self, mut ap: ...) -> u64 {
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| ^^^^^^^^^^^^^^ ...because method `dyn_method_ref` is C-variadic
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= help: consider moving `dyn_method_ref` to another trait
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= help: only type `Struct` implements `Trait`; consider using it directly instead.
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error: aborting due to 1 previous error
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For more information about this error, try `rustc --explain E0038`.
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