Add copy_cv documentation.

doc/copy_cv.qbk

@@ -0,0 +1,39 @@
+[/ 
+  Copyright 2015 Peter Dimov.
+  Distributed under the Boost Software License, Version 1.0.
+  (See accompanying file LICENSE_1_0.txt or copy at
+  http://www.boost.org/LICENSE_1_0.txt).
+]
+
+[section:copy_cv copy_cv]
+
+   template <class T, class U>
+   struct copy_cv
+   {
+      typedef __below type;
+   };
+  
+__type [^T /cv/], where /cv/ are the cv-qualifiers of `U`.
+
+__header ` #include <boost/type_traits/copy_cv.hpp>` or ` #include <boost/type_traits.hpp>`
+
+[table Examples
+
+[ [Expression] [Result Type]]
+
+[[`copy_cv<int, void>::type`][`int`]]
+
+[[`copy_cv<int const, void>::type`][`int const`]]
+
+[[`copy_cv<int, void const>::type`][`int const`]]
+
+[[`copy_cv<int volatile, void const>::type`][`int const volatile`]]
+
+[[`copy_cv<int&, void const>::type`] [`int&`]]
+
+[[`copy_cv<int*, void volatile>::type`] [`int* volatile`]]
+
+]
+
+[endsect]
+

doc/transform_traits.qbk

@@ -80,6 +80,9 @@ result of applying the transformation to the template argument `T`.
    template <class T>
    struct __remove_volatile;
 
+   template <class T, class U>
+   struct __copy_cv;
+
 [h4 Broken Compiler Workarounds:]
 
 For all of these templates support for partial specialization of class templates is 

doc/type_traits.qbk

@@ -132,6 +132,8 @@
 [def __decay [link boost_typetraits.reference.decay decay]]
 [def __is_complex [link boost_typetraits.reference.is_complex is_complex]]
 
+[def __copy_cv [link boost_typetraits.reference.copy_cv copy_cv]]
+
 A printer-friendly [@http://sourceforge.net/projects/boost/files/boost-docs/ 
  PDF version of this manual is also available].
 
@@ -183,6 +185,7 @@ that is the result of the transformation.
 [include alignment_of.qbk]
 [include conditional.qbk]
 [include common_type.qbk]
+[include copy_cv.qbk]
 [include decay.qbk]
 [include extent.qbk]
 [include floating_point_promotion.qbk]