From 9e96faf4c1db2b7350ffd698d5b7fdf4c4382d5a Mon Sep 17 00:00:00 2001
From: Beman <bdawes@acm.org>
Date: Sat, 11 May 2013 08:13:55 -0400
Subject: [PATCH] float showing signs of life.

---
 include/boost/endian/converters.hpp       | 24 ++++++++++++++++-------
 include/boost/endian/detail/intrinsic.hpp |  7 -------
 test/converter_test.cpp                   |  4 ++++
 3 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/include/boost/endian/converters.hpp b/include/boost/endian/converters.hpp
index 3c79ea3..112fd2a 100644
--- a/include/boost/endian/converters.hpp
+++ b/include/boost/endian/converters.hpp
@@ -13,6 +13,7 @@
 #include <boost/cstdint.hpp>
 #include <boost/endian/detail/intrinsic.hpp>
 #include <boost/detail/scoped_enum_emulation.hpp>
+#include <boost/static_assert.hpp>
 #include <algorithm>
 
 //------------------------------------- synopsis ---------------------------------------//
@@ -37,14 +38,9 @@ namespace endian
 
   //  reverse_bytes overloads for floating point types as requested by Vicente
   //  Botet and others.
-  // TODO: Need implementation
-  // TODO: Need to verify the return does not invoke undefined behavior (as might happen
-  // if there are unutterable floating point values, such as happens with the unutterable
-  // pointer values that cause an immediate abort on some legacy architectures
   // TODO: Track progress of Floating-Point Typedefs Having Specified Widths proposal (N3626)
-  // and add boost equivalent from Paul, Chris, John, if available
-  inline float    reverse_bytes(float x) BOOST_NOEXCEPT;    
-  inline double   reverse_bytes(double x) BOOST_NOEXCEPT;   
+  inline float    reverse_bytes(float x) BOOST_NOEXCEPT;
+  //inline double   reverse_bytes(double x) BOOST_NOEXCEPT;   
 
   //  general reverse_bytes function template to meet requests for UDT support by Vicente
   //  Botet and others. 
@@ -155,6 +151,20 @@ namespace endian
 # endif
   }
 
+  inline float reverse_bytes(float x) BOOST_NOEXCEPT
+  {
+    BOOST_STATIC_ASSERT_MSG(sizeof(float) == sizeof(uint32_t),
+      "boost::endian only supprts sizeof(float) == 4; please report error to boost mailing list");
+    uint32_t tmp = reverse_bytes(*(const uint32_t*)&x);
+    return *(const float*)&tmp;
+  }
+
+  //inline double reverse_bytes(double x) BOOST_NOEXCEPT
+  //{
+  //  BOOST_STATIC_ASSERT_MSG(sizeof(double) == sizeof(uint64_t),
+  //    "boost::endian only supprts sizeof(double) == 8; please report error to boost mailing list");
+  //}
+
 //  general reverse_bytes function template implementation approach using std::reverse
 //  suggested by Mathias Gaunard
   template <class T>
diff --git a/include/boost/endian/detail/intrinsic.hpp b/include/boost/endian/detail/intrinsic.hpp
index 63f6c72..1bf95ba 100644
--- a/include/boost/endian/detail/intrinsic.hpp
+++ b/include/boost/endian/detail/intrinsic.hpp
@@ -1,6 +1,5 @@
 // Copyright (C) 2012 David Stone
 // 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
 //
 // See http://www.boost.org/libs/endian/ for documentation.
@@ -15,12 +14,6 @@
 #  include <boost/cstdint.hpp>
 #endif
 
-
-#undef BOOST_ENDIAN_NO_INTRINSICS
-#undef BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_2
-#undef BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_4
-#undef BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_8
-
 #if (defined __GNUC__ || defined __clang__)
     #include <byteswap.h>
     #define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_2 bswap_16
diff --git a/test/converter_test.cpp b/test/converter_test.cpp
index a5f60d0..b349c65 100644
--- a/test/converter_test.cpp
+++ b/test/converter_test.cpp
@@ -306,6 +306,10 @@ int cpp_main(int, char * [])
   test_conditional_reverse_bytes();
   test_compile_time_convert_bytes();
   test_runtime_convert_bytes();
+
+  BOOST_TEST(be::reverse_bytes(1.0F) != 1.0F);
+  BOOST_TEST(be::reverse_bytes(be::reverse_bytes(1.0F)) == 1.0F);
+
   return ::boost::report_errors();
 }