1 files changed, 56 insertions, 0 deletions
diff --git a/tests/ui/fn/fn-pointer-mismatch.rs b/tests/ui/fn/fn-pointer-mismatch.rs
new file mode 100644
index 000000000..0597478cb
--- /dev/null
+++ b/tests/ui/fn/fn-pointer-mismatch.rs
@@ -0,0 +1,56 @@
+fn foo(x: u32) -> u32 {
+    x * 2
+}
+
+fn bar(x: u32) -> u32 {
+    x * 3
+}
+
+// original example from Issue #102608
+fn foobar(n: u32) -> u32 {
+    let g = if n % 2 == 0 { &foo } else { &bar };
+    //~^ ERROR `if` and `else` have incompatible types
+    //~| different fn items have unique types, even if their signatures are the same
+    g(n)
+}
+
+fn main() {
+    assert_eq!(foobar(7), 21);
+    assert_eq!(foobar(8), 16);
+
+    // general mismatch of fn item types
+    let mut a = foo;
+    a = bar;
+    //~^ ERROR mismatched types
+    //~| expected fn item `fn(_) -> _ {foo}`
+    //~| found fn item `fn(_) -> _ {bar}`
+    //~| different fn items have unique types, even if their signatures are the same
+
+    // display note even when boxed
+    let mut b = Box::new(foo);
+    b = Box::new(bar);
+    //~^ ERROR mismatched types
+    //~| different fn items have unique types, even if their signatures are the same
+
+    // suggest removing reference
+    let c: fn(u32) -> u32 = &foo;
+    //~^ ERROR mismatched types
+    //~| expected fn pointer `fn(u32) -> u32`
+    //~| found reference `&fn(u32) -> u32 {foo}`
+
+    // suggest using reference
+    let d: &fn(u32) -> u32 = foo;
+    //~^ ERROR mismatched types
+    //~| expected reference `&fn(u32) -> u32`
+    //~| found fn item `fn(u32) -> u32 {foo}`
+
+    // suggest casting with reference
+    let e: &fn(u32) -> u32 = &foo;
+    //~^ ERROR mismatched types
+    //~| expected reference `&fn(u32) -> u32`
+    //~| found reference `&fn(u32) -> u32 {foo}`
+
+    // OK
+    let mut z: fn(u32) -> u32 = foo as fn(u32) -> u32;
+    z = bar;
+}