Document assign-assign.rs

Author: jieyouxu

tests/ui/assign-assign.rs

@@ -1,5 +1,11 @@
+//! Regression test for [Using the result of an assignment expression results in an LLVM assert
+//! #483][issue-483]. This test checks that assignment expressions produce a unit type, and is
+//! properly lowered to LLVM IR such that it does not trigger an LLVM assertion. This test was added
+//! *really* early, back in 2011.
+//!
+//! [issue-483]: https://github.com/rust-lang/rust/issues/483
+
 //@ run-pass
-// Issue 483 - Assignment expressions result in nil
 
 fn test_assign() {
     let mut x: isize;
@@ -27,4 +33,7 @@ fn test_assign_op() {
     assert_eq!(z, ());
 }
 
-pub fn main() { test_assign(); test_assign_op(); }
+pub fn main() {
+    test_assign();
+    test_assign_op();
+}