1 files changed, 79 insertions, 0 deletions
diff --git a/tests/ui/coercion/coerce-to-bang.rs b/tests/ui/coercion/coerce-to-bang.rs
new file mode 100644
index 00000000000..1e06934d09f
--- /dev/null
+++ b/tests/ui/coercion/coerce-to-bang.rs
@@ -0,0 +1,79 @@
+#![feature(never_type)]
+
+fn foo(x: usize, y: !, z: usize) { }
+
+fn call_foo_a() {
+    foo(return, 22, 44);
+    //~^ ERROR mismatched types
+}
+
+fn call_foo_b() {
+    // Divergence happens in the argument itself, definitely ok.
+    foo(22, return, 44);
+}
+
+fn call_foo_c() {
+    // This test fails because the divergence happens **after** the
+    // coercion to `!`:
+    foo(22, 44, return); //~ ERROR mismatched types
+}
+
+fn call_foo_d() {
+    // This test passes because `a` has type `!`:
+    let a: ! = return;
+    let b = 22;
+    let c = 44;
+    foo(a, b, c); // ... and hence a reference to `a` is expected to diverge.
+    //~^ ERROR mismatched types
+}
+
+fn call_foo_e() {
+    // This test probably could pass but we don't *know* that `a`
+    // has type `!` so we don't let it work.
+    let a = return;
+    let b = 22;
+    let c = 44;
+    foo(a, b, c); //~ ERROR mismatched types
+}
+
+fn call_foo_f() {
+    // This fn fails because `a` has type `usize`, and hence a
+    // reference to is it **not** considered to diverge.
+    let a: usize = return;
+    let b = 22;
+    let c = 44;
+    foo(a, b, c); //~ ERROR mismatched types
+}
+
+fn array_a() {
+    // Return is coerced to `!` just fine, but `22` cannot be.
+    let x: [!; 2] = [return, 22]; //~ ERROR mismatched types
+}
+
+fn array_b() {
+    // Error: divergence has not yet occurred.
+    let x: [!; 2] = [22, return]; //~ ERROR mismatched types
+}
+
+fn tuple_a() {
+    // No divergence at all.
+    let x: (usize, !, usize) = (22, 44, 66); //~ ERROR mismatched types
+}
+
+fn tuple_b() {
+    // Divergence happens before coercion: OK
+    let x: (usize, !, usize) = (return, 44, 66);
+    //~^ ERROR mismatched types
+}
+
+fn tuple_c() {
+    // Divergence happens before coercion: OK
+    let x: (usize, !, usize) = (22, return, 66);
+}
+
+fn tuple_d() {
+    // Error: divergence happens too late
+    let x: (usize, !, usize) = (22, 44, return); //~ ERROR mismatched types
+}
+
+fn main() { }