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Diffstat (limited to '')
-rw-r--r-- | src/test/ui-fulldeps/issue-15924.rs | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src/test/ui-fulldeps/issue-15924.rs b/src/test/ui-fulldeps/issue-15924.rs new file mode 100644 index 000000000..d8b3914d0 --- /dev/null +++ b/src/test/ui-fulldeps/issue-15924.rs @@ -0,0 +1,53 @@ +// run-pass + +#![allow(unused_imports)] +#![allow(unused_must_use)] +// pretty-expanded FIXME #23616 + +use std::fmt; +use std::marker::PhantomData; + +trait Encoder { + type Error; +} + +trait Encodable<S: Encoder> { + fn encode(&self, s: &mut S) -> Result<(), S::Error>; +} + +impl<S: Encoder> Encodable<S> for i32 { + fn encode(&self, _s: &mut S) -> Result<(), S::Error> { + Ok(()) + } +} + +struct JsonEncoder<'a>(PhantomData<&'a mut ()>); + +impl Encoder for JsonEncoder<'_> { + type Error = (); +} + +fn encode_json<T: for<'r> Encodable<JsonEncoder<'r>>>( + object: &T, +) -> Result<String, ()> { + let s = String::new(); + { + let mut encoder = JsonEncoder(PhantomData); + object.encode(&mut encoder)?; + } + Ok(s) +} + +struct Foo<T: for<'a> Encodable<JsonEncoder<'a>>> { + v: T, +} + +impl<T: for<'a> Encodable<JsonEncoder<'a>>> Drop for Foo<T> { + fn drop(&mut self) { + encode_json(&self.v); + } +} + +fn main() { + let _ = Foo { v: 10 }; +} |