---

yaml
---
r: 229303
b: refs/heads/try
c: 5aa6c15
h: refs/heads/master
i:
  229301: bbf7d83
  229299: 19adffa
  229295: 3df7705
v: v3

Author: GuillaumeGomez

[refs]

@@ -1,7 +1,7 @@
 ---
 refs/heads/master: aca2057ed5fb7af3f8905b2bc01f72fa001c35c8
 refs/heads/snap-stage3: 1af31d4974e33027a68126fa5a5a3c2c6491824f
-refs/heads/try: 2a08cff97c94160ddd06cdec380bbde8bd4f1d1b
+refs/heads/try: 5aa6c155a3a5de2aa5a358e3d4f8ca212dece98f
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try/src/librustc_typeck/diagnostics.rs

@@ -1123,27 +1123,39 @@ You hit this error because the compiler lacks information to
 determine a type for this variable. Erroneous code example:
 
 ```
+fn demo(devil: fn () -> !) {
+    let x: &_ = devil();
+    // error: cannot determine a type for this local variable
+}
+
+fn oh_no() -> ! { panic!("the devil is in the details") }
+
 fn main() {
-    let x: &_; // error: cannot determine a type for this local variable
+    demo(oh_no);
 }
 ```
 
-You have two possibilities to solve this situation:
- * Give an explicit definition of the variable
- * Infer the variable
-
+To solve this situation, constrain the type of the variable.
 Examples:
 
 ```
-fn some_func(x: u32) {
+fn some_func(x: &u32) {
     // some code
 }
 
-fn main() {
-    let x = 0u32; // ok!
-    // or:
-    let x = 0;
+fn demo(devil: fn () -> !) {
+    let x: &u32 = devil();
+    // Here we defined the type at the variable creation
+
+    let x: &_ = devil();
     some_func(x);
+    // Here, the type is determined by the function argument type
+}
+
+fn oh_no() -> ! { panic!("the devil is in the details") }
+
+fn main() {
+    demo(oh_no);
 }
 ```
 "##,