Merge pull request #249 from RalfJung/ptr-layout

add note that pointer layout information is preliminary

Author: RalfJung

reference/src/layout/pointers.md

@@ -1,5 +1,11 @@
 # Layout of reference and pointer types
 
+**Disclaimer:** Everything this section says about pointers to dynamically sized
+types represents the consensus from issue [#16], but has not been stabilized
+through an RFC. As such, this is preliminary information.
+
+[#16]: https://github.com/rust-rfcs/unsafe-code-guidelines/issues/16
+
 ### Terminology
 
 Reference types are types of the form `&T`, `&mut T`.

reference/src/layout/scalars.md

@@ -1,9 +1,11 @@
 # Layout of scalar types
 
-This chapter represents the consensus from issue [#9]. It documents the memory
-layout and considerations for `bool`, `char`, floating point types (`f{32, 64}`),
-and integral types (`{i,u}{8,16,32,64,128,size}`).
+**Disclaimer:** This chapter represents the consensus from issue
+[#9].  The statements in here are not (yet) "guaranteed"
+not to change until an RFC ratifies them.
 
+This documents the memory layout and considerations for `bool`, `char`, floating
+point types (`f{32, 64}`), and integral types (`{i,u}{8,16,32,64,128,size}`).
 These types are all scalar types, representing a single value, and have no
 layout `#[repr()]` flags.