Fix Visual Studio 2013 build

Builds/VisualStudio2013/beast.vcxproj

@@ -253,6 +253,7 @@
     <ClInclude Include="..\..\beast\utility\PropertyStream.h" />
     <ClInclude Include="..\..\beast\utility\StaticObject.h" />
     <ClInclude Include="..\..\beast\utility\type_name.h" />
+    <ClInclude Include="..\..\beast\utility\zero.h" />
     <ClInclude Include="..\..\beast\Version.h" />
     <ClInclude Include="..\..\modules\beast_asio\async\AsyncObject.h" />
     <ClInclude Include="..\..\modules\beast_asio\basics\FixedInputBuffer.h" />
@@ -767,7 +768,7 @@
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
     </ClCompile>
-    <ClCompile Include="..\..\beast\utility\tests\hardened_hash.test.cpp">
+    <ClCompile Include="..\..\beast\utility\tests\Zero.test.cpp">
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>

Builds/VisualStudio2013/beast.vcxproj.filters

@@ -1201,6 +1201,9 @@
     <ClInclude Include="..\..\beast\utility\type_name.h">
       <Filter>beast\utility</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\beast\utility\zero.h">
+      <Filter>beast\utility</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\modules\beast_core\files\DirectoryIterator.cpp">
@@ -1647,9 +1650,6 @@
     <ClCompile Include="..\..\beast\threads\tests\Atomic.test.cpp">
       <Filter>beast\threads\tests</Filter>
     </ClCompile>
-    <ClCompile Include="..\..\beast\utility\tests\hardened_hash.test.cpp">
-      <Filter>beast\utility\tests</Filter>
-    </ClCompile>
     <ClCompile Include="..\..\beast\crypto\tests\BinaryEncoding.cpp">
       <Filter>beast\crypto\tests</Filter>
     </ClCompile>
@@ -1665,6 +1665,9 @@
     <ClCompile Include="..\..\beast\container\impl\spookyv2.cpp">
       <Filter>beast\container\impl</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\beast\utility\tests\Zero.test.cpp">
+      <Filter>beast\utility\tests</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <Text Include="..\..\TODO.txt">

beast/utility/Zero.h

@@ -22,6 +22,9 @@
 
 #include "../config/CompilerConfig.h"
 
+// VS2013 SP1 fails with decltype return
+#define BEAST_NO_ZERO_AUTO_RETURN 1
+
 namespace beast {
 
 /** Zero allows classes to offer efficient comparisons to zero.
@@ -39,102 +42,122 @@ namespace beast {
     returns a positive number, 0, or a negative; or there needs to be a signum
     function which resolves in the namespace which takes an instance of T and
     returns a positive, zero or negative number.
- */
+*/
 
-struct Zero {};
+struct Zero
+{
+};
 
 namespace {
-
 static BEAST_CONSTEXPR Zero zero{};
+}
 
-}  // namespace
-
-/** The default implementation of signum calls the method on the class.
-
-    Calls to signum must be made from a namespace that does not include
-    overloads of the function.
- */
+/** Default implementation of signum calls the method on the class. */
 template <typename T>
-auto signum(T const& t) -> decltype(t.signum()) {
+#if BEAST_NO_ZERO_AUTO_RETURN
+int signum(T const& t)
+#else
+auto signum(T const& t) -> decltype(t.signum())
+#endif
+{
     return t.signum();
 }
 
 namespace detail {
 namespace zero_helper {
 
+// For argument dependent lookup to function properly, calls to signum must
+// be made from a namespace that does not include overloads of the function..
 template <class T>
-auto call_signum (T const& t) -> decltype(signum(t)) {
+#if BEAST_NO_ZERO_AUTO_RETURN
+int call_signum (T const& t)
+#else
+auto call_signum(T const& t) -> decltype(t.signum())
+#endif
+{
     return signum(t);
 }
 
 } // zero_helper
 } // detail
 
-/** Handle operators where T is on the left side using signum. */
+// Handle operators where T is on the left side using signum.
+
 template <typename T>
-bool operator==(T const& t, Zero) {
+bool operator==(T const& t, Zero)
+{
     return detail::zero_helper::call_signum(t) == 0;
 }
 
 template <typename T>
-bool operator!=(T const& t, Zero) {
+bool operator!=(T const& t, Zero)
+{
     return detail::zero_helper::call_signum(t) != 0;
 }
 
 template <typename T>
-bool operator>(T const& t, Zero) {
-    return detail::zero_helper::call_signum(t) > 0;
-}
-
-template <typename T>
-bool operator>=(T const& t, Zero) {
-    return detail::zero_helper::call_signum(t) >= 0;
-}
-
-template <typename T>
-bool operator<(T const& t, Zero) {
+bool operator<(T const& t, Zero)
+{
     return detail::zero_helper::call_signum(t) < 0;
 }
 
 template <typename T>
-bool operator<=(T const& t, Zero) {
+bool operator>(T const& t, Zero)
+{
+    return detail::zero_helper::call_signum(t) > 0;
+}
+
+template <typename T>
+bool operator>=(T const& t, Zero)
+{
+    return detail::zero_helper::call_signum(t) >= 0;
+}
+
+template <typename T>
+bool operator<=(T const& t, Zero)
+{
     return detail::zero_helper::call_signum(t) <= 0;
 }
 
+// Handle operators where T is on the right side by
+// reversing the operation, so that T is on the left side.
 
-/** Handle operators where T is on the right side by reversing the operation,
-    so that T is on the left side.
- */
 template <typename T>
-bool operator==(Zero, T const& t) {
+bool operator==(Zero, T const& t)
+{
     return t == zero;
 }
 
 template <typename T>
-bool operator!=(Zero, T const& t) {
+bool operator!=(Zero, T const& t)
+{
     return t != zero;
 }
 
 template <typename T>
-bool operator>(Zero, T const& t) {
-    return t < zero;
-}
-
-template <typename T>
-bool operator>=(Zero, T const& t) {
-    return t <= zero;
-}
-
-template <typename T>
-bool operator<(Zero, T const& t) {
+bool operator<(Zero, T const& t)
+{
     return t > zero;
 }
 
 template <typename T>
-bool operator<=(Zero, T const& t) {
+bool operator>(Zero, T const& t)
+{
+    return t < zero;
+}
+
+template <typename T>
+bool operator>=(Zero, T const& t)
+{
+    return t <= zero;
+}
+
+template <typename T>
+bool operator<=(Zero, T const& t)
+{
     return t >= zero;
 }
 
-}  // beast
+} // beast
 
 #endif

beast/utility/tests/Zero.test.cpp

@@ -25,14 +25,20 @@ namespace beast {
 
 struct adl_tester {};
 
-int signum (adl_tester) { return 0; }
+int signum (adl_tester)
+{
+    return 0;
+}
 
 
 namespace detail {
 
 struct adl_tester2 {};
 
-int signum (adl_tester2) { return 0; }
+int signum (adl_tester2)
+{
+    return 0;
+}
 
 }  // detail