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Diffstat (limited to 'src/test/ui/regions/regions-early-bound-lifetime-in-assoc-fn.rs')
-rw-r--r-- | src/test/ui/regions/regions-early-bound-lifetime-in-assoc-fn.rs | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/src/test/ui/regions/regions-early-bound-lifetime-in-assoc-fn.rs b/src/test/ui/regions/regions-early-bound-lifetime-in-assoc-fn.rs new file mode 100644 index 000000000..fe50a7dd1 --- /dev/null +++ b/src/test/ui/regions/regions-early-bound-lifetime-in-assoc-fn.rs @@ -0,0 +1,35 @@ +// run-pass +#![allow(unused_imports)] +// Test that we are able to compile calls to associated fns like +// `decode()` where the bound on the `Self` parameter references a +// lifetime parameter of the trait. This example indicates why trait +// lifetime parameters must be early bound in the type of the +// associated item. + +// pretty-expanded FIXME #23616 + +use std::marker; + +pub enum Value<'v> { + A(&'v str), + B, +} + +pub trait Decoder<'v> { + fn read(&mut self) -> Value<'v>; +} + +pub trait Decodable<'v, D: Decoder<'v>> { + fn decode(d: &mut D) -> Self; +} + +impl<'v, D: Decoder<'v>> Decodable<'v, D> for () { + fn decode(d: &mut D) -> () { + match d.read() { + Value::A(..) => (), + Value::B => Decodable::decode(d), + } + } +} + +pub fn main() { } |