6.3

1 files changed, 30 insertions, 36 deletions

diff --git a/zen/win_ver.h b/zen/win_ver.h
index 2c5e2f81..8797b596 100644
--- a/zen/win_ver.h
+++ b/zen/win_ver.h
@@ -7,19 +7,28 @@
 #ifndef WINDOWS_VERSION_HEADER_238470348254325
 #define WINDOWS_VERSION_HEADER_238470348254325
 
+#include <cstdint>
 #include <zen/win.h> //includes "windows.h"
 
 namespace zen
 {
-bool winXpOrLater();
-bool winServer2003orLater();
-bool vistaOrLater();
-bool win7OrLater();
-bool win8OrLater();
-
-
+std::uint64_t getOsVersion();
+std::uint64_t toBigOsNumber(DWORD high, DWORD low);
 
+//version overview: http://msdn.microsoft.com/en-us/library/ms724834(VS.85).aspx
+const std::uint64_t osVersionWin81         = toBigOsNumber(6, 3);
+const std::uint64_t osVersionWin8          = toBigOsNumber(6, 2);
+const std::uint64_t osVersionWin7          = toBigOsNumber(6, 1);
+const std::uint64_t osVersionWinVista      = toBigOsNumber(6, 0);
+const std::uint64_t osVersionWinServer2003 = toBigOsNumber(5, 2);
+const std::uint64_t osVersionWinXp         = toBigOsNumber(5, 1);
 
+inline bool win81OrLater        () { return getOsVersion() >= osVersionWin81;         }
+inline bool win8OrLater         () { return getOsVersion() >= osVersionWin8;          }
+inline bool win7OrLater         () { return getOsVersion() >= osVersionWin7;          }
+inline bool vistaOrLater        () { return getOsVersion() >= osVersionWinVista;      }
+inline bool winServer2003orLater() { return getOsVersion() >= osVersionWinServer2003; }
+inline bool winXpOrLater        () { return getOsVersion() >= osVersionWinXp;         }
 
 
 
@@ -29,42 +38,27 @@ bool win8OrLater();
 
 
 //######################### implementation #########################
-//version overview: http://msdn.microsoft.com/en-us/library/ms724834(VS.85).aspx
+inline
+std::uint64_t toBigOsNumber(DWORD high, DWORD low)
+{
+    ULARGE_INTEGER tmp = {};
+    tmp.HighPart = high;
+    tmp.LowPart  = low;
+
+    static_assert(sizeof(tmp) == sizeof(std::uint64_t), "");
+    return tmp.QuadPart;
+}
 
-//2000        is version 5.0
-//XP          is version 5.1
-//Server 2003 is version 5.2
-//Vista       is version 6.0
-//Seven       is version 6.1
-//Eight       is version 6.2
 
-namespace impl
-{
 inline
-bool winXyOrLater(DWORD major, DWORD minor)
+std::uint64_t getOsVersion()
 {
     OSVERSIONINFO osvi = {};
     osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
-    if (::GetVersionEx(&osvi)) //38 ns per call! (yes, that's nano!) -> we do NOT miss C++11 thread safe statics right now...
-        return osvi.dwMajorVersion != major ? osvi.dwMajorVersion > major : osvi.dwMinorVersion >= minor;
-    return false;
-}
+    if (!::GetVersionEx(&osvi)) //38 ns per call! (yes, that's nano!) -> we do NOT miss C++11 thread safe statics right now...
+        return 0;
+    return toBigOsNumber(osvi.dwMajorVersion, osvi.dwMinorVersion);
 }
-
-inline
-bool winXpOrLater() { return impl::winXyOrLater(5, 1); }
-
-inline
-bool winServer2003orLater() { return impl::winXyOrLater(5, 2); }
-
-inline
-bool vistaOrLater() { return impl::winXyOrLater(6, 0); }
-
-inline
-bool win7OrLater() { return impl::winXyOrLater(6, 1); }
-
-inline
-bool win8OrLater() { return impl::winXyOrLater(6, 2); }
 }
 
 #endif //WINDOWS_VERSION_HEADER_238470348254325