diff options
Diffstat (limited to 'tests/ui/coherence/coherence-wasm-bindgen.rs')
-rw-r--r-- | tests/ui/coherence/coherence-wasm-bindgen.rs | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/tests/ui/coherence/coherence-wasm-bindgen.rs b/tests/ui/coherence/coherence-wasm-bindgen.rs new file mode 100644 index 000000000..ee09a7244 --- /dev/null +++ b/tests/ui/coherence/coherence-wasm-bindgen.rs @@ -0,0 +1,37 @@ +// Capture a coherence pattern from wasm-bindgen that we discovered as part of +// future-compatibility warning #56105. This pattern currently receives a lint +// warning but we probably want to support it long term. +// +// Key distinction: we are implementing once for `A` (take ownership) and one +// for `&A` (borrow). +// +// c.f. #56105 + +#![deny(coherence_leak_check)] + +trait IntoWasmAbi { + fn some_method(&self) {} +} + +trait FromWasmAbi {} +trait RefFromWasmAbi {} +trait ReturnWasmAbi {} + +impl<'a, 'b, A, R> IntoWasmAbi for &'a (dyn Fn(A) -> R + 'b) +where + A: FromWasmAbi, + R: ReturnWasmAbi, +{ +} + +// Explicitly writing the bound lifetime. +impl<'a, 'b, A, R> IntoWasmAbi for &'a (dyn for<'x> Fn(&'x A) -> R + 'b) +where + A: RefFromWasmAbi, + R: ReturnWasmAbi, +{ + //~^^^^^ ERROR conflicting implementation + //~| WARNING this was previously accepted +} + +fn main() {} |