Add STATIC_ASSERT() macro and use it

src/basicmacros.h

@@ -38,4 +38,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 	C(const C &);             \
 	C &operator=(const C &)
 
+// Fail compilation if condition expr is not met.
+// Note that 'msg' must follow the format of a valid identifier, e.g.
+// STATIC_ASSERT(sizeof(foobar_t) == 40), foobar_t_is_wrong_size);
+#define STATIC_ASSERT(expr, msg) typedef char msg[!!(expr) * 2 - 1]
+
 #endif