+// noinline
+#ifdef _MSC_VER
+# define FOLLY_NOINLINE __declspec(noinline)
+#elif defined(__clang__) || defined(__GNUC__)
+# define FOLLY_NOINLINE __attribute__((noinline))
+#else
+# define FOLLY_NOINLINE
+#endif
+
+// always inline
+#ifdef _MSC_VER
+# define FOLLY_ALWAYS_INLINE __forceinline
+#elif defined(__clang__) || defined(__GNUC__)
+# define FOLLY_ALWAYS_INLINE inline __attribute__((always_inline))
+#else
+# define FOLLY_ALWAYS_INLINE
+#endif
+
+// detection for 64 bit
+#if defined(__x86_64__) || defined(_M_X64)
+# define FOLLY_X64 1
+#else
+# define FOLLY_X64 0
+#endif
+
+// packing is very ugly in msvc
+#ifdef _MSC_VER
+# define FOLLY_PACK_ATTR /**/
+# define FOLLY_PACK_PUSH __pragma(pack(push, 1))
+# define FOLLY_PACK_POP __pragma(pack(pop))
+#elif defined(__clang__) || defined(__GNUC__)
+# define FOLLY_PACK_ATTR __attribute__((packed))
+# define FOLLY_PACK_PUSH /**/
+# define FOLLY_PACK_POP /**/
+#else
+# define FOLLY_PACK_ATTR /**/
+# define FOLLY_PACK_PUSH /**/
+# define FOLLY_PACK_POP /**/
+#endif