rust/tests/ui/never_type/never-value-fallback-issue-...

32 lines
704 B
Rust

// Regression test for #66757
//
// Test than when you have a `!` value (e.g., the local variable
// never) and an uninferred variable (here the argument to `From`) it
// doesn't fallback to `()` but rather `!`.
//
//@ revisions: nofallback fallback
//@[fallback] run-pass
//@[nofallback] check-fail
#![feature(never_type)]
#![cfg_attr(fallback, feature(never_type_fallback))]
struct E;
impl From<!> for E {
fn from(_: !) -> E {
E
}
}
#[allow(unreachable_code)]
#[allow(dead_code)]
#[allow(unused_must_use)]
fn foo(never: !) {
<E as From<!>>::from(never); // Ok
<E as From<_>>::from(never); //[nofallback]~ ERROR trait bound `E: From<()>` is not satisfied
}
fn main() { }