iox-#27 Add constraints to the request and response types of client and server

Author: elBoberido

iceoryx_posh/include/iceoryx_posh/internal/popo/client_impl.hpp

@@ -35,6 +35,16 @@ namespace popo
 template <typename Req, typename Res, typename BaseClientT = BaseClient<>>
 class ClientImpl : public BaseClientT, public RpcInterface<Request<Req>>
 {
+    static_assert(!std::is_void<Req>::value, "The type `Req` must not be void. Use the UntypedClient for void types.");
+    static_assert(!std::is_void<Res>::value, "The type `Res` must not be void. Use the UntypedClient for void types.");
+
+    static_assert(!std::is_const<Req>::value, "The type `Req` must not be const.");
+    static_assert(!std::is_const<Res>::value, "The type `Res` must not be const.");
+    static_assert(!std::is_reference<Req>::value, "The type `Req` must not be a reference.");
+    static_assert(!std::is_reference<Res>::value, "The type `Res` must not be a reference.");
+    static_assert(!std::is_pointer<Req>::value, "The type `Req` must not be a pointer.");
+    static_assert(!std::is_pointer<Res>::value, "The type `Res` must not be a pointer.");
+
   public:
     explicit ClientImpl(const capro::ServiceDescription& service, const ClientOptions& clientOptions = {}) noexcept;
     ClientImpl(const ClientImpl&) = delete;

iceoryx_posh/include/iceoryx_posh/internal/popo/server_impl.hpp

@@ -35,6 +35,16 @@ namespace popo
 template <typename Req, typename Res, typename BaseServerT = BaseServer<>>
 class ServerImpl : public BaseServerT, public RpcInterface<Response<Res>>
 {
+    static_assert(!std::is_void<Req>::value, "The type `Req` must not be void. Use the UntypedServer for void types.");
+    static_assert(!std::is_void<Res>::value, "The type `Res` must not be void. Use the UntypedServer for void types.");
+
+    static_assert(!std::is_const<Req>::value, "The type `Req` must not be const.");
+    static_assert(!std::is_const<Res>::value, "The type `Res` must not be const.");
+    static_assert(!std::is_reference<Req>::value, "The type `Req` must not be a reference.");
+    static_assert(!std::is_reference<Res>::value, "The type `Res` must not be a reference.");
+    static_assert(!std::is_pointer<Req>::value, "The type `Req` must not be a pointer.");
+    static_assert(!std::is_pointer<Res>::value, "The type `Res` must not be a pointer.");
+
   public:
     explicit ServerImpl(const capro::ServiceDescription& service, const ServerOptions& serverOptions = {}) noexcept;
     ServerImpl(const ServerImpl&) = delete;