For at least c++14 mode for compiling protobuf stub

Author: andersfugmann

test/dune

@@ -35,7 +35,8 @@
  (foreign_stubs
   (language cxx)
   (names protobuf2json)
-  (flags (:standard (:include c_flags.sexp))))
+  ;; set std=c++14 after standard and before derived c flags
+  (flags (:standard "-std=c++14" (:include c_flags.sexp)) ))
  (c_library_flags (:standard (:include c_library_flags.sexp)))
 )
 

test/protobuf2json.cc

@@ -53,14 +53,14 @@ util::TypeResolver* make_resolver(const std::string include, const std::string p
 #ifdef USE_FILESYSTEM
         for(const auto& p : std::filesystem::directory_iterator(".")) {
             if(p.path().extension() == ".proto") {
-                auto * fd = importer->Import(p.path().filename());
+                importer->Import(p.path().filename());
             }
         }
 #else
         caml_invalid_argument("No protofile specified");
 #endif
     } else {
-        auto * fd = importer->Import(proto_file);
+        importer->Import(proto_file);
     }
     return util::NewTypeResolverForDescriptorPool("type.googleapis.com", importer->pool());
 }