The following test case (taken from rustc's testsuite) doesn't parse:
// build-pass (FIXME(62277): could be check-pass?)
#![allow(bare_trait_objects)]
type A = Box<(Fn(u8) -> u8) + 'static + Send + Sync>; // OK (but see #39318)
fn main() {}
Besides being already controversial (check out the issue referenced) and one hell of an edge case, bare trait objects are on their way out.
The following test case (taken from
rustc's testsuite) doesn't parse:Besides being already controversial (check out the issue referenced) and one hell of an edge case, bare trait objects are on their way out.