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-rw-r--r--src/test/ui/coercion/coerce-issue-49593-box-never.rs58
1 files changed, 58 insertions, 0 deletions
diff --git a/src/test/ui/coercion/coerce-issue-49593-box-never.rs b/src/test/ui/coercion/coerce-issue-49593-box-never.rs
new file mode 100644
index 000000000..16efb65ac
--- /dev/null
+++ b/src/test/ui/coercion/coerce-issue-49593-box-never.rs
@@ -0,0 +1,58 @@
+// revisions: nofallback fallback
+// ignore-windows - the number of `Error` impls is platform-dependent
+//[fallback] check-pass
+//[nofallback] check-fail
+
+#![feature(never_type)]
+#![cfg_attr(fallback, feature(never_type_fallback))]
+#![allow(unreachable_code)]
+
+use std::error::Error;
+use std::mem;
+
+fn raw_ptr_box<T>(t: T) -> *mut T {
+ panic!()
+}
+
+fn foo(x: !) -> Box<dyn Error> {
+ /* *mut $0 is coerced to Box<dyn Error> here */ Box::<_ /* ! */>::new(x)
+ //[nofallback]~^ ERROR trait bound `(): std::error::Error` is not satisfied
+}
+
+fn foo_raw_ptr(x: !) -> *mut dyn Error {
+ /* *mut $0 is coerced to *mut Error here */ raw_ptr_box::<_ /* ! */>(x)
+ //[nofallback]~^ ERROR trait bound `(): std::error::Error` is not satisfied
+}
+
+fn no_coercion(d: *mut dyn Error) -> *mut dyn Error {
+ /* an unsize coercion won't compile here, and it is indeed not used
+ because there is nothing requiring the _ to be Sized */
+ d as *mut _
+}
+
+trait Xyz {}
+struct S;
+struct T;
+impl Xyz for S {}
+impl Xyz for T {}
+
+fn foo_no_never() {
+ let mut x /* : Option<S> */ = None;
+ let mut first_iter = false;
+ loop {
+ if !first_iter {
+ let y: Box<dyn Xyz>
+ = /* Box<$0> is coerced to Box<Xyz> here */ Box::new(x.unwrap());
+ }
+
+ x = Some(S);
+ first_iter = true;
+ }
+
+ let mut y : Option<S> = None;
+ // assert types are equal
+ mem::swap(&mut x, &mut y);
+}
+
+fn main() {
+}