From f8ecd668201d0bcc9e854dc913cc714204f97d69 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Thu, 12 Oct 2023 14:06:30 +0300
Subject: [PATCH] Move integrals to detail/hash_integral.hpp

---
 .../container_hash/detail/hash_integral.hpp   | 102 ++++++++++++++++++
 include/boost/container_hash/hash.hpp         |  86 +--------------
 2 files changed, 104 insertions(+), 84 deletions(-)
 create mode 100644 include/boost/container_hash/detail/hash_integral.hpp

diff --git a/include/boost/container_hash/detail/hash_integral.hpp b/include/boost/container_hash/detail/hash_integral.hpp
new file mode 100644
index 0000000..ecac3c4
--- /dev/null
+++ b/include/boost/container_hash/detail/hash_integral.hpp
@@ -0,0 +1,102 @@
+// Copyright 2021-203 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#ifndef BOOST_HASH_DETAIL_HASH_INTEGRAL_HPP
+#define BOOST_HASH_DETAIL_HASH_INTEGRAL_HPP
+
+#include <boost/container_hash/detail/hash_mix.hpp>
+#include <type_traits>
+#include <cstddef>
+#include <climits>
+
+namespace boost
+{
+namespace hash_detail
+{
+
+template<class T,
+    bool bigger_than_size_t = (sizeof(T) > sizeof(std::size_t)),
+    bool is_unsigned = std::is_unsigned<T>::value,
+    std::size_t size_t_bits = sizeof(std::size_t) * CHAR_BIT,
+    std::size_t type_bits = sizeof(T) * CHAR_BIT>
+struct hash_integral_impl;
+
+template<class T, bool is_unsigned, std::size_t size_t_bits, std::size_t type_bits> struct hash_integral_impl<T, false, is_unsigned, size_t_bits, type_bits>
+{
+    static std::size_t fn( T v )
+    {
+        return static_cast<std::size_t>( v );
+    }
+};
+
+template<class T, std::size_t size_t_bits, std::size_t type_bits> struct hash_integral_impl<T, true, false, size_t_bits, type_bits>
+{
+    static std::size_t fn( T v )
+    {
+        typedef typename std::make_unsigned<T>::type U;
+
+        if( v >= 0 )
+        {
+            return hash_integral_impl<U>::fn( static_cast<U>( v ) );
+        }
+        else
+        {
+            return ~hash_integral_impl<U>::fn( static_cast<U>( ~static_cast<U>( v ) ) );
+        }
+    }
+};
+
+template<class T> struct hash_integral_impl<T, true, true, 32, 64>
+{
+    static std::size_t fn( T v )
+    {
+        std::size_t seed = 0;
+
+        seed = static_cast<std::size_t>( v >> 32 ) + hash_detail::hash_mix( seed );
+        seed = static_cast<std::size_t>( v  & 0xFFFFFFFF ) + hash_detail::hash_mix( seed );
+
+        return seed;
+    }
+};
+
+template<class T> struct hash_integral_impl<T, true, true, 32, 128>
+{
+    static std::size_t fn( T v )
+    {
+        std::size_t seed = 0;
+
+        seed = static_cast<std::size_t>( v >> 96 ) + hash_detail::hash_mix( seed );
+        seed = static_cast<std::size_t>( v >> 64 ) + hash_detail::hash_mix( seed );
+        seed = static_cast<std::size_t>( v >> 32 ) + hash_detail::hash_mix( seed );
+        seed = static_cast<std::size_t>( v ) + hash_detail::hash_mix( seed );
+
+        return seed;
+    }
+};
+
+template<class T> struct hash_integral_impl<T, true, true, 64, 128>
+{
+    static std::size_t fn( T v )
+    {
+        std::size_t seed = 0;
+
+        seed = static_cast<std::size_t>( v >> 64 ) + hash_detail::hash_mix( seed );
+        seed = static_cast<std::size_t>( v ) + hash_detail::hash_mix( seed );
+
+        return seed;
+    }
+};
+
+} // namespace hash_detail
+
+template <typename T>
+typename std::enable_if<std::is_integral<T>::value, std::size_t>::type
+    hash_value( T v )
+{
+    return hash_detail::hash_integral_impl<T>::fn( v );
+}
+
+} // namespace boost
+
+#endif // #ifndef BOOST_HASH_DETAIL_HASH_INTEGRAL_HPP
diff --git a/include/boost/container_hash/hash.hpp b/include/boost/container_hash/hash.hpp
index f523c96..36bd1bc 100644
--- a/include/boost/container_hash/hash.hpp
+++ b/include/boost/container_hash/hash.hpp
@@ -15,6 +15,7 @@
 #include <boost/container_hash/is_contiguous_range.hpp>
 #include <boost/container_hash/is_unordered_range.hpp>
 #include <boost/container_hash/is_described_class.hpp>
+#include <boost/container_hash/detail/hash_integral.hpp>
 #include <boost/container_hash/detail/hash_tuple_like.hpp>
 #include <boost/container_hash/detail/hash_mix.hpp>
 #include <boost/container_hash/detail/hash_range.hpp>
@@ -67,90 +68,7 @@ namespace boost
     //
 
     // integral types
-
-    namespace hash_detail
-    {
-        template<class T,
-            bool bigger_than_size_t = (sizeof(T) > sizeof(std::size_t)),
-            bool is_unsigned = std::is_unsigned<T>::value,
-            std::size_t size_t_bits = sizeof(std::size_t) * CHAR_BIT,
-            std::size_t type_bits = sizeof(T) * CHAR_BIT>
-        struct hash_integral_impl;
-
-        template<class T, bool is_unsigned, std::size_t size_t_bits, std::size_t type_bits> struct hash_integral_impl<T, false, is_unsigned, size_t_bits, type_bits>
-        {
-            static std::size_t fn( T v )
-            {
-                return static_cast<std::size_t>( v );
-            }
-        };
-
-        template<class T, std::size_t size_t_bits, std::size_t type_bits> struct hash_integral_impl<T, true, false, size_t_bits, type_bits>
-        {
-            static std::size_t fn( T v )
-            {
-                typedef typename std::make_unsigned<T>::type U;
-
-                if( v >= 0 )
-                {
-                    return hash_integral_impl<U>::fn( static_cast<U>( v ) );
-                }
-                else
-                {
-                    return ~hash_integral_impl<U>::fn( static_cast<U>( ~static_cast<U>( v ) ) );
-                }
-            }
-        };
-
-        template<class T> struct hash_integral_impl<T, true, true, 32, 64>
-        {
-            static std::size_t fn( T v )
-            {
-                std::size_t seed = 0;
-
-                seed = static_cast<std::size_t>( v >> 32 ) + hash_detail::hash_mix( seed );
-                seed = static_cast<std::size_t>( v  & 0xFFFFFFFF ) + hash_detail::hash_mix( seed );
-
-                return seed;
-            }
-        };
-
-        template<class T> struct hash_integral_impl<T, true, true, 32, 128>
-        {
-            static std::size_t fn( T v )
-            {
-                std::size_t seed = 0;
-
-                seed = static_cast<std::size_t>( v >> 96 ) + hash_detail::hash_mix( seed );
-                seed = static_cast<std::size_t>( v >> 64 ) + hash_detail::hash_mix( seed );
-                seed = static_cast<std::size_t>( v >> 32 ) + hash_detail::hash_mix( seed );
-                seed = static_cast<std::size_t>( v ) + hash_detail::hash_mix( seed );
-
-                return seed;
-            }
-        };
-
-        template<class T> struct hash_integral_impl<T, true, true, 64, 128>
-        {
-            static std::size_t fn( T v )
-            {
-                std::size_t seed = 0;
-
-                seed = static_cast<std::size_t>( v >> 64 ) + hash_detail::hash_mix( seed );
-                seed = static_cast<std::size_t>( v ) + hash_detail::hash_mix( seed );
-
-                return seed;
-            }
-        };
-
-    } // namespace hash_detail
-
-    template <typename T>
-    typename std::enable_if<std::is_integral<T>::value, std::size_t>::type
-        hash_value( T v )
-    {
-        return hash_detail::hash_integral_impl<T>::fn( v );
-    }
+	//   in detail/hash_integral.hpp
 
     // enumeration types