--- libecb/ecb.h	2013/12/04 10:17:49	1.125
+++ libecb/ecb.h	2014/01/09 05:16:12	1.128
@@ -89,13 +89,21 @@
   #endif
 #endif
 
-#define ECB_C     (__STDC__+0) /* this assumes that __STDC__ is either empty or a number */
-#define ECB_C99   (__STDC_VERSION__ >= 199901L)
-#define ECB_C11   (__STDC_VERSION__ >= 201112L)
 #define ECB_CPP   (__cplusplus+0)
 #define ECB_CPP11 (__cplusplus >= 201103L)
 
 #if ECB_CPP
+  #define ECB_C            0
+  #define ECB_STDC_VERSION 0
+#else
+  #define ECB_C            1
+  #define ECB_STDC_VERSION __STDC_VERSION__
+#endif
+
+#define ECB_C99   (ECB_STDC_VERSION >= 199901L)
+#define ECB_C11   (ECB_STDC_VERSION >= 201112L)
+
+#if ECB_CPP
   #define ECB_EXTERN_C extern "C"
   #define ECB_EXTERN_C_BEG ECB_EXTERN_C {
   #define ECB_EXTERN_C_END }
@@ -167,6 +175,8 @@
   #if ECB_GCC_VERSION(4,7)
     /* see comment below (stdatomic.h) about the C11 memory model. */
     #define ECB_MEMORY_FENCE         __atomic_thread_fence (__ATOMIC_SEQ_CST)
+    #define ECB_MEMORY_FENCE_ACQUIRE __atomic_thread_fence (__ATOMIC_ACQUIRE)
+    #define ECB_MEMORY_FENCE_RELEASE __atomic_thread_fence (__ATOMIC_RELEASE)
 
   /* The __has_feature syntax from clang is so misdesigned that we cannot use it
    * without risking compile time errors with other compilers. We *could*
@@ -175,10 +185,18 @@
    * #elif defined __clang && __has_feature (cxx_atomic)
    *   // see comment below (stdatomic.h) about the C11 memory model.
    *   #define ECB_MEMORY_FENCE         __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)
+   *   #define ECB_MEMORY_FENCE_ACQUIRE __c11_atomic_thread_fence (__ATOMIC_ACQUIRE)
+   *   #define ECB_MEMORY_FENCE_RELEASE __c11_atomic_thread_fence (__ATOMIC_RELEASE)
    */
 
   #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
     #define ECB_MEMORY_FENCE         __sync_synchronize ()
+  #elif _MSC_VER >= 1500 /* VC++ 2008 */
+    /* apparently, microsoft broke all the memory barrier stuff in Visual Studio 2008... */
+    #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
+    #define ECB_MEMORY_FENCE         _ReadWriteBarrier (); MemoryBarrier()
+    #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier (); MemoryBarrier() /* according to msdn, _ReadBarrier is not a load fence */
+    #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier (); MemoryBarrier()
   #elif _MSC_VER >= 1400 /* VC++ 2005 */
     #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
     #define ECB_MEMORY_FENCE         _ReadWriteBarrier ()
@@ -208,6 +226,8 @@
     /* for most usages, or gcc and clang have a bug */
     /* I *currently* lean towards the latter, and inefficiently implement */
     /* all three of ecb's fences as a seq_cst fence */
+    /* Update, gcc-4.8 generates mfence for all c++ fences, but nothing */
+    /* for all __atomic_thread_fence's except seq_cst */
     #define ECB_MEMORY_FENCE         atomic_thread_fence (memory_order_seq_cst)
   #endif
 #endif
@@ -274,6 +294,11 @@
   #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
 #else
   #define ecb_attribute(attrlist)
+
+  /* possible C11 impl for integral types
+  typedef struct ecb_is_constant_struct ecb_is_constant_struct;
+  #define ecb_is_constant(expr)          _Generic ((1 ? (struct ecb_is_constant_struct *)0 : (void *)((expr) - (expr)), ecb_is_constant_struct *: 0, default: 1)) */
+
   #define ecb_is_constant(expr)          0
   #define ecb_expect(expr,value)         (expr)
   #define ecb_prefetch(addr,rw,locality)