--- /dev/null
+// build-pass
+#![allow(incomplete_features)]
+
+#![feature(const_generics)]
+pub struct Vector<T, const N: usize>([T; N]);
+
+pub type TruncatedVector<T, const N: usize> = Vector<T, { N - 1 }>;
+
+impl<T, const N: usize> Vector<T, { N }> {
+ /// Drop the last component and return the vector with one fewer dimension.
+ pub fn trunc(self) -> (TruncatedVector<T, { N }>, T) {
+ unimplemented!()
+ }
+}
+
+fn vec4<T>(a: T, b: T, c: T, d: T) -> Vector<T, 4> {
+ Vector([a, b, c, d])
+}
+
+fn main() {
+ let (_xyz, _w): (TruncatedVector<u32, 4>, u32) = vec4(0u32, 1, 2, 3).trunc();
+}