Add boost/core/bit.hpp (bit_cast, rotl, rotr)

test/bit_cast_test.cpp

@@ -0,0 +1,29 @@
+// Test for boost/core/bit.hpp
+//
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/core/bit.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/cstdint.hpp>
+#include <cstring>
+
+int main()
+{
+    {
+        float x = 0.89f;
+        boost::uint32_t y = boost::core::bit_cast<boost::uint32_t>( x );
+
+        BOOST_TEST( std::memcmp( &x, &y, sizeof(x) ) == 0 );
+    }
+
+    {
+        double x = 0.89;
+        boost::uint64_t y = boost::core::bit_cast<boost::uint64_t>( x );
+
+        BOOST_TEST( std::memcmp( &x, &y, sizeof(x) ) == 0 );
+    }
+
+    return boost::report_errors();
+}