Ported msgpack#962 to C++.

Improved alignment calculation logic.

Author: redboltz

include/msgpack/sysdep.hpp

@@ -26,6 +26,13 @@
     typedef unsigned __int32 uint32_t;
     typedef signed __int64 int64_t;
     typedef unsigned __int64 uint64_t;
+#   if defined(_WIN64)
+        typedef signed __int64 intptr_t;
+        typedef unsigned __int64 uintptr_t;
+#   else
+        typedef signed __int32 intptr_t;
+        typedef unsigned __int32 uintptr_t;
+#   endif
 #elif defined(_MSC_VER)  // && _MSC_VER >= 1600
 #   include <stdint.h>
 #else

include/msgpack/v1/detail/cpp11_zone.hpp

@@ -232,8 +232,8 @@ inline char* zone::get_aligned(char* ptr, size_t align)
 {
     return
         reinterpret_cast<char*>(
-            reinterpret_cast<size_t>(
-            (ptr + (align - 1))) / align * align);
+            reinterpret_cast<uintptr_t>(
+                (ptr + (align - 1))) & ~static_cast<uintptr_t>(align - 1));
 }
 
 inline void* zone::allocate_align(size_t size, size_t align)