common: use decltype to approximate typeof for C++.

decltype looks good enough to approximate some usage of the
very handy gcc-compatible typeof extension. It does not seem
to be good enough to cover all cases (one known cas where it
breaks down is mrp_list_entry).

diff --git a/src/common/macros.h b/src/common/macros.h
index bee5741..78e8f1c 100644 (file)
--- a/src/common/macros.h
+++ b/src/common/macros.h
@@ -37,6 +37,10 @@
 #    define TRUE (!FALSE)
 #endif
 
+#ifdef __cplusplus
+#  define typeof(expr) decltype(expr)
+#endif
+
 /** Align ptr to multiple of align. */
 #define MRP_ALIGN(ptr, align) (((ptr) + ((align)-1)) & ~((align)-1))