[Boost-commit] svn:boost r76032 - trunk/boost/random/detail

Subject: [Boost-commit] svn:boost r76032 - trunk/boost/random/detail
From: dnljms_at_[hidden]
Date: 2011-12-18 06:16:48

Author: danieljames
Date: 2011-12-18 06:16:47 EST (Sun, 18 Dec 2011)
New Revision: 76032
URL: http://svn.boost.org/trac/boost/changeset/76032

Log:
Use a proper constexpr for integer_log2.
Text files modified: 
   trunk/boost/random/detail/integer_log2.hpp |    21 +++++++++++++++++----                   
   1 files changed, 17 insertions(+), 4 deletions(-)

Modified: trunk/boost/random/detail/integer_log2.hpp
==============================================================================
--- trunk/boost/random/detail/integer_log2.hpp	(original)
+++ trunk/boost/random/detail/integer_log2.hpp	2011-12-18 06:16:47 EST (Sun, 18 Dec 2011)
@@ -35,13 +35,26 @@
 template<int Shift>
 struct integer_log2_impl
 {
+#if defined(BOOST_NO_CONSTEXPR)
     template<class T>
-    BOOST_RANDOM_DETAIL_CONSTEXPR static int apply(T t, int accum,
-            int update = 0)
+    BOOST_RANDOM_DETAIL_CONSTEXPR static int apply(T t, int accum)
+    {
+        int update = ((t >> Shift) != 0) * Shift;
+        return integer_log2_impl<Shift / 2>::apply(t >> update, accum + update);
+    }
+#else
+    template<class T>
+    BOOST_RANDOM_DETAIL_CONSTEXPR static int apply2(T t, int accum, int update)
+    {
+        return integer_log2_impl<Shift / 2>::apply(t >> update, accum + update);
+    }
+
+    template<class T>
+    BOOST_RANDOM_DETAIL_CONSTEXPR static int apply(T t, int accum)
     {
-        return update = ((t >> Shift) != 0) * Shift,
-            integer_log2_impl<Shift / 2>::apply(t >> update, accum + update);
+        return apply2(t, accum, ((t >> Shift) != 0) * Shift);
     }
+#endif
 };
 
 template<>