check for _MSC_VER as well as __STDC__ when deciding to use the ## operator
or not
diff --git a/include/curl/curl.h b/include/curl/curl.h
index a535475..a621775 100644
--- a/include/curl/curl.h
+++ b/include/curl/curl.h
@@ -209,7 +209,7 @@
#ifdef CINIT
#undef CINIT
#endif
-#ifdef __STDC__
+#if defined(__STDC__) || defined(_MSC_VER)
#define CINIT(name,type,number) CURLOPT_ ## name = CURLOPTTYPE_ ## type + number
#else
/* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */
@@ -595,7 +595,8 @@
#ifdef CFINIT
#undef CFINIT
#endif
-#ifdef __STDC__
+
+#if defined(__STDC__) || defined(_MSC_VER)
#define CFINIT(name) CURLFORM_ ## name
#else
/* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */
