diff options
Diffstat (limited to 'src/test/ui/span/issue28498-reject-ex1.rs')
-rw-r--r-- | src/test/ui/span/issue28498-reject-ex1.rs | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/src/test/ui/span/issue28498-reject-ex1.rs b/src/test/ui/span/issue28498-reject-ex1.rs new file mode 100644 index 000000000..4d1b41255 --- /dev/null +++ b/src/test/ui/span/issue28498-reject-ex1.rs @@ -0,0 +1,37 @@ +// Example taken from RFC 1238 text + +// https://github.com/rust-lang/rfcs/blob/master/text/1238-nonparametric-dropck.md +// #examples-of-code-that-will-start-to-be-rejected + +// Compare against test/run-pass/issue28498-must-work-ex2.rs + +use std::cell::Cell; + +struct Concrete<'a>(u32, Cell<Option<&'a Concrete<'a>>>); + +struct Foo<T> { data: Vec<T> } + +fn potentially_specialized_wrt_t<T>(t: &T) { + // Hypothetical code that does one thing for generic T and then is + // specialized for T == Concrete (and the specialized form can + // then access a reference held in concrete tuple). + // + // (We don't have specialization yet, but we want to allow for it + // in the future.) +} + +impl<T> Drop for Foo<T> { + fn drop(&mut self) { + potentially_specialized_wrt_t(&self.data[0]) + } +} + +fn main() { + let mut foo = Foo { data: Vec::new() }; + foo.data.push(Concrete(0, Cell::new(None))); + foo.data.push(Concrete(0, Cell::new(None))); + + foo.data[0].1.set(Some(&foo.data[1])); + //~^ ERROR borrow may still be in use when destructor runs + foo.data[1].1.set(Some(&foo.data[0])); +} |