From 9c0d2b246589d7329d78e93afc04d270278e6ada Mon Sep 17 00:00:00 2001
From: Nathan Kleyn <nathan@nathankleyn.com>
Date: Wed, 12 Aug 2015 18:07:56 +0100
Subject: [PATCH 1/2] Add detailed diagnostics for E0383.

This adds detailed diagnostics for E0383, 'partial reinitialization of
uninitialized structure'.

This is part of rust-lang/rust#24407.
---
 src/librustc_borrowck/diagnostics.rs | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/librustc_borrowck/diagnostics.rs b/src/librustc_borrowck/diagnostics.rs
index 850701e704613..acd2bf3fba9d6 100644
--- a/src/librustc_borrowck/diagnostics.rs
+++ b/src/librustc_borrowck/diagnostics.rs
@@ -138,6 +138,30 @@ Book:
 https://doc.rust-lang.org/book/ownership.html
 "##,
 
+E0383: r##"
+This error occurs when an attempt is made to partially reinitialize a
+structure that is currently uninitialized.
+
+For example, this can happen when a transfer of ownership has taken place:
+
+```
+let mut t = Test { a: 1, b: None};
+let mut u = Test { a: 2, b: Some(Box::new(t))}; // `t` is now uninitialized
+                                                // because ownership has been
+                                                // transferred
+t.b = Some(Box::new(u)); // error, partial reinitialization of uninitialized
+                         //        structure `t`
+```
+
+This error can be fixed by fully reinitializing the structure in question:
+
+```
+let mut t = Test { a: 1, b: None};
+let mut u = Test { a: 2, b: Some(Box::new(t))};
+t = Test { a: 1, b: Some(Box::new(u))};
+```
+"##,
+
 E0384: r##"
 This error occurs when an attempt is made to reassign an immutable variable.
 For example:
@@ -217,7 +241,6 @@ https://doc.rust-lang.org/std/cell/
 }
 
 register_diagnostics! {
-    E0383, // partial reinitialization of uninitialized structure
     E0385, // {} in an aliasable location
     E0386, // {} in an immutable container
     E0388, // {} in a static location

From 67c7fd710be56cf3ba5ca03b7291add856e73a8d Mon Sep 17 00:00:00 2001
From: Nathan Kleyn <nathan@nathankleyn.com>
Date: Thu, 13 Aug 2015 09:11:06 +0100
Subject: [PATCH 2/2] Improve code examples for E0383 long diagnostic.

---
 src/librustc_borrowck/diagnostics.rs | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/src/librustc_borrowck/diagnostics.rs b/src/librustc_borrowck/diagnostics.rs
index acd2bf3fba9d6..0bc439529260c 100644
--- a/src/librustc_borrowck/diagnostics.rs
+++ b/src/librustc_borrowck/diagnostics.rs
@@ -142,23 +142,20 @@ E0383: r##"
 This error occurs when an attempt is made to partially reinitialize a
 structure that is currently uninitialized.
 
-For example, this can happen when a transfer of ownership has taken place:
+For example, this can happen when a drop has taken place:
 
 ```
-let mut t = Test { a: 1, b: None};
-let mut u = Test { a: 2, b: Some(Box::new(t))}; // `t` is now uninitialized
-                                                // because ownership has been
-                                                // transferred
-t.b = Some(Box::new(u)); // error, partial reinitialization of uninitialized
-                         //        structure `t`
+let mut x = Foo { a: 1 };
+drop(x); // `x` is now uninitialized
+x.a = 2; // error, partial reinitialization of uninitialized structure `t`
 ```
 
 This error can be fixed by fully reinitializing the structure in question:
 
 ```
-let mut t = Test { a: 1, b: None};
-let mut u = Test { a: 2, b: Some(Box::new(t))};
-t = Test { a: 1, b: Some(Box::new(u))};
+let mut x = Foo { a: 1 };
+drop(x);
+x = Foo { a: 2 };
 ```
 "##,