---

yaml
---
r: 16031
b: refs/heads/try
c: 4ffe34c
h: refs/heads/master
i:
  16029: ebb73a2
  16027: 98477f7
  16023: 0ed5c5c
  16015: b4e18c3
  15999: 5ba5733
v: v3

Author: eholk

[refs]

@@ -2,5 +2,5 @@
 refs/heads/master: 61b1875c16de39c166b0f4d54bba19f9c6777d1a
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 4a81779abd786ff22d71434c6d9a5917ea4cdfff
-refs/heads/try: 8b6bfc96cba80dd59c244acbb27487e28ef8280f
+refs/heads/try: 4ffe34cacee85685652d3fcea7e3874b5e23ed73
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105

branches/try/src/rustc/middle/kind.rs

@@ -9,15 +9,28 @@ import util::ppaux::{ty_to_str, tys_to_str};
 import syntax::print::pprust::expr_to_str;
 import freevars::freevar_entry;
 
-// Kind analysis pass. There are three kinds:
+// Kind analysis pass.
 //
-//  sendable: scalar types, and unique types containing only sendable types
-//  copyable: boxes, closures, and uniques containing copyable types
-//  noncopyable: resources, or unique types containing resources
+// There are several kinds defined by various operations. The most restrictive
+// kind is noncopyable. The noncopyable kind can be extended with any number
+// of the following attributes.
+//
+//  send: Things that can be sent on channels or included in spawned closures.
+//  copy: Things that can be copied.
+//  const: Things thare are deeply immutable. They are guaranteed never to
+//    change, and can be safely shared without copying between tasks.
+//
+// Send includes scalar types, resources and unique types containing only
+// sendable types.
+//
+// Copy includes boxes, closure and unique types containing copyable types.
+//
+// Const include scalar types, things without non-const fields, and pointers
+// to const things.
 //
 // This pass ensures that type parameters are only instantiated with types
 // whose kinds are equal or less general than the way the type parameter was
-// annotated (with the `send` or `copy` keyword).
+// annotated (with the `send`, `copy` or `const` keyword).
 //
 // It also verifies that noncopyable kinds are not copied. Sendability is not
 // applied, since none of our language primitives send. Instead, the sending