tweak from cjefferson
llvm-svn: 103656
diff --git a/libcxx/www/index.html b/libcxx/www/index.html
index bcef628..474cdbe 100644
--- a/libcxx/www/index.html
+++ b/libcxx/www/index.html
@@ -72,7 +72,8 @@
to how they are implemented. For example, it is generally accepted that
building std::string using the "short string optimization" instead of
using Copy On Write (COW) is a superior approach for multicore
- machines. Breaking ABI compatibility with old versions of the library was
+ machines (particularly in C++'0x, which has rvalue references). Breaking
+ ABI compatibility with old versions of the library was
determined to be critical to achieving the performance goals of
libc++.</p></li>
