---

yaml
---
r: 92232
b: refs/heads/auto
c: 76d9a96
h: refs/heads/master
v: v3

Author: nikomatsakis

[refs]

@@ -13,7 +13,7 @@ refs/heads/try3: 9387340aab40a73e8424c48fd42f0c521a4875c0
 refs/tags/release-0.3.1: 495bae036dfe5ec6ceafd3312b4dca48741e845b
 refs/tags/release-0.4: e828ea2080499553b97dfe33b3f4d472b4562ad7
 refs/tags/release-0.5: 7e3bcfbf21278251ee936ad53e92e9b719702d73
-refs/heads/auto: 1252947fa976c30ef99961e197e25e86c69621c4
+refs/heads/auto: 76d9a9671bf456407c1b8fd029a4a1149684fb5b
 refs/heads/servo: af82457af293e2a842ba6b7759b70288da276167
 refs/tags/release-0.6: b4ebcfa1812664df5e142f0134a5faea3918544c
 refs/tags/0.1: b19db808c2793fe2976759b85a355c3ad8c8b336

branches/auto/src/librustc/middle/borrowck/doc.rs

@@ -215,6 +215,24 @@ of this rule: there are comments in the borrowck source referencing
 these names, so that you can cross reference to find the actual code
 that corresponds to the formal rule.
 
+### Invariants
+
+I want to collect, at a high-level, the invariants the borrow checker
+maintains. I will give them names and refer to them throughout the
+text. Together these invariants are crucial for the overall soundness
+of the system.
+
+**Mutability requires uniqueness.** To mutate a path
+
+**Unique mutability.** There is only one *usable* mutable path to any
+given memory at any given time. This implies that when claiming memory
+with an expression like `p = &mut x`, the compiler must guarantee that
+the borrowed value `x` can no longer be mutated so long as `p` is
+live. (This is done via restrictions, read on.)
+
+**.**
+
+
 ### The `gather_loans` pass
 
 We start with the `gather_loans` pass, which walks the AST looking for

branches/auto/src/test/run-pass/borrowck-borrow-of-mut-base-ptr-safe.rs

@@ -21,5 +21,5 @@ fn foo<'a>(mut t0: &'a mut int,
     let r: &int = &*t0; // ...after all, could do same thing directly.
 }
 
-fn main() {
+pub fn main() {
 }

branches/auto/src/test/run-pass/borrowck-freeze-frozen-mut.rs

@@ -30,7 +30,7 @@ pub fn main() {
         assert_eq!(*index1, 2);
         assert_eq!(*index2, 3);
     }
-    assert_eq!(data[0], 1);
+    assert_eq!(data[0], 5);
     assert_eq!(data[1], 2);
     assert_eq!(data[2], 3);
 }