1 files changed, 93 insertions, 0 deletions
diff --git a/ext/boost/functional/hash/detail/hash_float_generic.hpp b/ext/boost/functional/hash/detail/hash_float_generic.hpp
new file mode 100644
index 0000000000..f9acee9cd1
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+++ b/ext/boost/functional/hash/detail/hash_float_generic.hpp
@@ -0,0 +1,93 @@
+
+// Copyright 2005-2009 Daniel James.
+// 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)
+
+// A general purpose hash function for non-zero floating point values.
+
+#if !defined(BOOST_FUNCTIONAL_HASH_DETAIL_HASH_FLOAT_GENERIC_HEADER)
+#define BOOST_FUNCTIONAL_HASH_DETAIL_HASH_FLOAT_GENERIC_HEADER
+
+#include <boost/functional/hash/detail/float_functions.hpp>
+#include <boost/integer/static_log2.hpp>
+#include <boost/functional/hash/detail/limits.hpp>
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+#if defined(BOOST_MSVC)
+#pragma warning(push)
+#if BOOST_MSVC >= 1400
+#pragma warning(disable:6294) // Ill-defined for-loop: initial condition does
+                              // not satisfy test. Loop body not executed 
+#endif
+#endif
+
+namespace boost
+{
+    namespace hash_detail
+    {
+        inline void hash_float_combine(std::size_t& seed, std::size_t value)
+        {
+            seed ^= value + (seed<<6) + (seed>>2);
+        }
+
+        template <class T>
+        inline std::size_t float_hash_impl2(T v)
+        {
+            boost::hash_detail::call_frexp<T> frexp;
+            boost::hash_detail::call_ldexp<T> ldexp;
+        
+            int exp = 0;
+
+            v = frexp(v, &exp);
+
+            // A postive value is easier to hash, so combine the
+            // sign with the exponent and use the absolute value.
+            if(v < 0) {
+                v = -v;
+                exp += limits<T>::max_exponent -
+                    limits<T>::min_exponent;
+            }
+
+            // The result of frexp is always between 0.5 and 1, so its
+            // top bit will always be 1. Subtract by 0.5 to remove that.
+            v -= T(0.5);
+            v = ldexp(v, limits<std::size_t>::digits + 1);
+            std::size_t seed = static_cast<std::size_t>(v);
+            v -= seed;
+
+            // ceiling(digits(T) * log2(radix(T))/ digits(size_t)) - 1;
+            std::size_t const length
+                = (limits<T>::digits *
+                        boost::static_log2<limits<T>::radix>::value - 1)
+                / limits<std::size_t>::digits;
+
+            for(std::size_t i = 0; i != length; ++i)
+            {
+                v = ldexp(v, limits<std::size_t>::digits);
+                std::size_t part = static_cast<std::size_t>(v);
+                v -= part;
+                hash_float_combine(seed, part);
+            }
+
+            hash_float_combine(seed, exp);
+
+            return seed;
+        }
+
+        template <class T>
+        inline std::size_t float_hash_impl(T v)
+        {
+            typedef BOOST_DEDUCED_TYPENAME select_hash_type<T>::type type;
+            return float_hash_impl2(static_cast<type>(v));
+        }
+    }
+}
+
+#if defined(BOOST_MSVC)
+#pragma warning(pop)
+#endif
+
+#endif