1 files changed, 74 insertions, 0 deletions
diff --git a/tests/ui/pattern/slice-patterns-irrefutable.rs b/tests/ui/pattern/slice-patterns-irrefutable.rs
new file mode 100644
index 000000000..bd230608e
--- /dev/null
+++ b/tests/ui/pattern/slice-patterns-irrefutable.rs
@@ -0,0 +1,74 @@
+// Test that we infer the expected type of a pattern to an array of the given length.
+
+#![allow(unused_variables)]
+
+use std::array::TryFromSliceError;
+use std::convert::TryInto;
+
+struct Zeroes;
+impl Into<[usize; 2]> for Zeroes {
+    fn into(self) -> [usize; 2] {
+        [0; 2]
+    }
+}
+impl Into<[usize; 3]> for Zeroes {
+    fn into(self) -> [usize; 3] {
+        [0; 3]
+    }
+}
+impl Into<[usize; 4]> for Zeroes {
+    fn into(self) -> [usize; 4] {
+        [0; 4]
+    }
+}
+
+fn zeroes_into() {
+    let [a, b, c] = Zeroes.into();
+    let [d, e, f]: [_; 3] = Zeroes.into();
+}
+
+fn array_try_from(x: &[usize]) -> Result<usize, TryFromSliceError> {
+    let [a, b] = x.try_into()?;
+    Ok(a + b)
+}
+
+fn destructuring_assignment() {
+    let a: i32;
+    let b;
+    [a, b] = Default::default();
+}
+
+fn test_nested_array() {
+    let a: [_; 3];
+    let b;
+    //~^ ERROR type annotations needed
+    [a, b] = Default::default();
+}
+
+fn test_nested_array_type_hint() {
+    let a: [_; 3];
+    let b;
+    [a, b] = Default::default();
+    let _: i32 = b[1];
+}
+
+fn test_working_nested_array() {
+    let a: i32;
+    [[a, _, _], _, _] = Default::default();
+}
+
+struct Foo<T>([T; 2]);
+
+impl<T: Default + Copy> Default for Foo<T> {
+    fn default() -> Self {
+        Foo([Default::default(); 2])
+    }
+}
+
+fn field_array() {
+    let a: i32;
+    let b;
+    Foo([a, b]) = Default::default();
+}
+
+fn main() {}