[Boost-commit] svn:boost r61943 - in sandbox/SOC/2010/bit_masks/boost/integer: . details

Subject: [Boost-commit] svn:boost r61943 - in sandbox/SOC/2010/bit_masks/boost/integer: . details
From: bbartmanboost_at_[hidden]
Date: 2010-05-13 09:41:06

Author: bbartman
Date: 2010-05-13 09:41:05 EDT (Thu, 13 May 2010)
New Revision: 61943
URL: http://svn.boost.org/trac/boost/changeset/61943

Log:
working on high low bit metafunctions
Added:
   sandbox/SOC/2010/bit_masks/boost/integer/high_low_bits.hpp   (contents, props changed)
Text files modified: 
   sandbox/SOC/2010/bit_masks/boost/integer/bit_mask.hpp              |    42 ++----------------------------          
   sandbox/SOC/2010/bit_masks/boost/integer/details/bit_mask_impl.hpp |    54 +++++++++++++++++++++++++++++++-------- 
   2 files changed, 46 insertions(+), 50 deletions(-)

Modified: sandbox/SOC/2010/bit_masks/boost/integer/bit_mask.hpp
==============================================================================
--- sandbox/SOC/2010/bit_masks/boost/integer/bit_mask.hpp	(original)
+++ sandbox/SOC/2010/bit_masks/boost/integer/bit_mask.hpp	2010-05-13 09:41:05 EDT (Thu, 13 May 2010)
@@ -10,7 +10,6 @@
 #define BOOST_INTEGER_BIT_MASK_HPP
 
 // boost dependencies.
-#include <boost/mpl/int.hpp>
 
 
 
@@ -19,48 +18,15 @@
 namespace boost {
 
 
-/** Intention of this mask is to provide a simple mask which can be used
- *  to make simplified masks which are used for contigious bits.
- *  This needs to evolve into a specialization of the regular
- *  bit_mask.
+/** bit_mask.
+ *  Mask which creates a mask give type, offset and width of the mask
  */
-template <  typename MaskedType,
-            typename MaskOffsetInBits,
-            typename MaskWidth >
-struct simple_bit_mask;
-
-
-
-// forward declaration of the bit mask structure which will all 
-// a recursive definition of how
-template <typename Value, typename SecondValue = mpl::int_<0> >
-struct bit_mask;
-
-
-
-
-// termination specialization this will cause the psudo-recursive definition 
-// being evalueated to finish.
-template <int NewMaskValue, int CurrentMaskValue>
-struct bit_mask< mpl::int_< NewMaskValue >, mpl::int_< CurrentMaskValue > >
-    :mpl::bitor_<
-        mpl::int_<NewMaskValue>,
-        mpl::int_< CurrentMaskValue >
-    >::type
+template <typename T, typename Offset, typename Width>
+struct bit_maks
 { };
 
 
 
-// this is the recursive step for the bit_mask.
-template <int MaskValue, int CurrentMaskValue>
-struct bit_mask < bit_mask< mpl::int_<MaskValue> >, mpl::int_<CurrentMaskValue> >
-    :mpl::bitor_<
-        mpl::int_< CurrentMaskValue >,
-        bit_mask< mpl::int_< MaskValue > >
-    >::type
-{ };
-
-
 } // namespace boost
 
 #endif

Modified: sandbox/SOC/2010/bit_masks/boost/integer/details/bit_mask_impl.hpp
==============================================================================
--- sandbox/SOC/2010/bit_masks/boost/integer/details/bit_mask_impl.hpp	(original)
+++ sandbox/SOC/2010/bit_masks/boost/integer/details/bit_mask_impl.hpp	2010-05-13 09:41:05 EDT (Thu, 13 May 2010)
@@ -1,5 +1,8 @@
 #ifndef BOOST_BIT_MASK_IMPL_HPP
 #define BOOST_BIT_MASK_IMPL_HPP
+
+#include <boost/mpl/integral_c.hpp>
+#include <boost/type_traits.hpp>
 #include <boost/mpl/bitwise.hpp>
 #include <boost/static_assert.hpp>
 
@@ -7,6 +10,22 @@
 
 
 
+/** Type which is used during specialization to infer that a template patameter
+ *  has not been used in the initilization of bit_mask_impl.
+ */
+struct unused_type { };
+
+/** Forward Declaration for the bit_mask_impl.
+ *  This is being used for specifying default parameters so they can be used in 
+ *  specializations to see how may parameters bit_mask_impl was called with.
+ *  If I had variadic templates this would be less of an issue.
+ */
+template <  typename MaskedType,
+            typename MaskOffsetInBits = unused_type ,
+            typename MaskWidth = unused_type >
+struct bit_mask_impl;
+
+
 
 /** Houses the structure for creating simple masks as well as 
  *  implements the preconditions for a simple_bit_mask.
@@ -20,12 +39,13 @@
  *
  *  3. Valid range for mask width is > 0.
  *  
- * 
+ *  4. The type which is being masked must satisfy the is_integral type trait.
  */
 template <  typename MaskedType,
             typename MaskOffsetInBits,
             typename MaskWidth >
-struct simple_bit_mask_impl {
+struct bit_mask_impl {
+
 
     // precondition 1.
     BOOST_STATIC_ASSERT(( (MaskOffsetInBits::value + MaskWidth::value)
@@ -35,22 +55,32 @@
 
     // precondition 3.
     BOOST_STATIC_ASSERT(( MaskWidth::value > 0 ));
+    
+    // precondition 4.
+    BOOST_STATIC_ASSERT(( is_integral<MaskedType>::value ));
+
 
-    // this is supposed to make decalring a static constant easy.
-//    BOOST_STATIC_CONSTANT( MaskedType, value = ( ) );
+    // this is supposed to make decalring a static constant easy, I think...
+    // BOOST_STATIC_CONSTANT( MaskedType, value = ( ) );
 
     // type typedef
-    typedef simple_bit_mask_impl<   MaskedType,
-                                    MaskOffsetInBits,
-                                    MaskWidth
-                                >   type;
-
-    typedef MaskedType              mask_type;
-    typedef MaskOffsetInBits        bit_offset;
-    typedef MaskWidth               mask_width;
+    typedef bit_mask_impl<   MaskedType,
+                             MaskOffsetInBits,
+                             MaskWidth
+                         >   type;
+
+    typedef MaskedType       mask_type;
+    typedef MaskOffsetInBits bit_offset;
+    typedef MaskWidth        mask_width;
 };
 
 
+/** bit_mask_impl specialization over an mpl type. */
+template < typename MaskedType, typename IntegralType, IntegralType IntegralValue>
+struct bit_mask_impl< MaskedType, mpl::integral_c<IntegralType, IntegralValue>, unused_type>{
+
+};
+
 } // end of details namespace.
 } // end of boost namespace.
 

Added: sandbox/SOC/2010/bit_masks/boost/integer/high_low_bits.hpp
==============================================================================