Add test/detail_rot.cpp

test/Jamfile

@@ -32,6 +32,7 @@ run get_integral_result.cpp ;
 
 run detail_read.cpp ;
 run detail_write.cpp ;
+run detail_rot.cpp ;
 
 # hash_append
 

test/detail_rot.cpp

@@ -0,0 +1,34 @@
+// Copyright 2024 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/hash2/detail/rot.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <array>
+
+int main()
+{
+    using namespace boost::hash2::detail;
+
+    {
+        std::uint32_t v = 0x9e3779b9;
+
+        for( int k = 1; k < 32; ++k )
+        {
+            BOOST_TEST_EQ( rotl( v, k ), ( v << k ) + ( v >> ( 32 - k ) ) );
+            BOOST_TEST_EQ( rotr( v, k ), ( v >> k ) + ( v << ( 32 - k ) ) );
+        }
+    }
+
+    {
+        std::uint64_t v = 0x9e3779b97f4a7c15;
+
+        for( int k = 1; k < 64; ++k )
+        {
+            BOOST_TEST_EQ( rotl( v, k ), ( v << k ) + ( v >> ( 64 - k ) ) );
+            BOOST_TEST_EQ( rotr( v, k ), ( v >> k ) + ( v << ( 64 - k ) ) );
+        }
+    }
+
+    return boost::report_errors();
+}