test the wrapper for message.

src/wrapper.hh

@@ -96,6 +96,8 @@ public:
         return value!=b.value;
     }
     
+    const T* operator->() const { return value; }
+    
     const T* get() const { return value; }
     T*  move_out()       { T* r = value; value=nullptr; return r;}
 

test/unittest_message.cc

@@ -0,0 +1,11 @@
+#include <gtest/gtest.h>
+
+#include "../src/types.hh"
+
+
+TEST( MessageTest, Simple )
+{
+    pEp::Message msg{PEP_dir_outgoing, "\r\n"};
+    
+    EXPECT_EQ(msg->dir, PEP_dir_outgoing);
+}