File: alias-bounds-when-not-wf.rs

package info (click to toggle)
rustc-web 1.78.0%2Bdfsg1-2~deb11u3
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 1,245,360 kB
  • sloc: xml: 147,985; javascript: 18,022; sh: 11,083; python: 10,265; ansic: 6,172; cpp: 5,023; asm: 4,390; makefile: 4,269
file content (19 lines) | stat: -rw-r--r-- 583 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
//@ compile-flags: -Znext-solver

#![feature(lazy_type_alias)]
//~^ WARN the feature `lazy_type_alias` is incomplete

trait Foo {}

type A<T: Foo> = T;

struct W<T>(T);

// For `W<A<usize>>` to be WF, `A<usize>: Sized` must hold. However, when assembling
// alias bounds for `A<usize>`, we try to normalize it, but it doesn't hold because
// `usize: Foo` doesn't hold. Therefore we ICE, because we don't expect to still
// encounter weak types in `assemble_alias_bound_candidates_recur`.
fn hello(_: W<A<usize>>) {}
//~^ ERROR the type `W<A<usize>>` is not well-formed

fn main() {}