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Diffstat (limited to '')
-rw-r--r-- | src/test/ui/issues/issue-23485.rs | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/src/test/ui/issues/issue-23485.rs b/src/test/ui/issues/issue-23485.rs new file mode 100644 index 000000000..1dd3d9293 --- /dev/null +++ b/src/test/ui/issues/issue-23485.rs @@ -0,0 +1,50 @@ +// run-pass +#![allow(unused_imports)] +// Test for an ICE that occurred when a default method implementation +// was applied to a type that did not meet the prerequisites. The +// problem occurred specifically because normalizing +// `Self::Item::Target` was impossible in this case. + +use std::boxed::Box; +use std::marker::Sized; +use std::clone::Clone; +use std::ops::Deref; +use std::option::Option; +use std::option::Option::{Some,None}; + +trait Iterator { + type Item; + + fn next(&mut self) -> Option<Self::Item>; + + fn clone_first(mut self) -> Option<<Self::Item as Deref>::Target> where + Self: Sized, + Self::Item: Deref, + <Self::Item as Deref>::Target: Clone, + { + self.next().map(|x| x.clone()) + } +} + +struct Counter { + value: i32 +} + +struct Token { + value: i32 +} + +impl Iterator for Counter { + type Item = Token; + + fn next(&mut self) -> Option<Token> { + let x = self.value; + self.value += 1; + Some(Token { value: x }) + } +} + +fn main() { + let mut x: Box<dyn Iterator<Item=Token>> = Box::new(Counter { value: 22 }); + assert_eq!(x.next().unwrap().value, 22); +} |