diff --git a/demo/src/Bindings.cpp b/demo/src/Bindings.cpp
index 0fa12db..4585441 100644
--- a/demo/src/Bindings.cpp
+++ b/demo/src/Bindings.cpp
@@ -14,18 +14,7 @@ namespace {
             return QVariant();
         }
     };
-
-    struct option_QString {
-    public:
-        QString value;
-        bool some;
-        operator QVariant() const {
-            if (some) {
-                return QVariant::fromValue(value);
-            }
-            return QVariant();
-        }
-    };
+    static_assert(std::is_pod<option_quintptr>::value, "option_quintptr must be a POD type.");
 
     struct option_quint64 {
     public:
@@ -38,6 +27,7 @@ namespace {
             return QVariant();
         }
     };
+    static_assert(std::is_pod<option_quint64>::value, "option_quint64 must be a POD type.");
 
     typedef void (*qstring_set)(QString* val, const char* utf8, int nbytes);
     void set_qstring(QString* val, const char* utf8, int nbytes) {
diff --git a/src/cpp.cpp b/src/cpp.cpp
index 8522da3..841e4e1 100644
--- a/src/cpp.cpp
+++ b/src/cpp.cpp
@@ -958,7 +958,8 @@ void writeCpp(const Configuration& conf) {
 namespace {
 )").arg(conf.hFile.fileName());
     for (auto option: conf.optionalTypes()) {
-        cpp << QString(R"(
+        if (option != "QString") {
+            cpp << QString(R"(
     struct option_%1 {
     public:
         %1 value;
@@ -970,7 +971,9 @@ namespace {
             return QVariant();
         }
     };
+    static_assert(std::is_pod<option_%1>::value, "option_%1 must be a POD type.");
 )").arg(option);
+        }
     }
     if (conf.types().contains("QString")) {
         cpp << R"(
diff --git a/tests/test_list_rust.cpp b/tests/test_list_rust.cpp
index df22d67..65181fb 100644
--- a/tests/test_list_rust.cpp
+++ b/tests/test_list_rust.cpp
@@ -14,6 +14,7 @@ namespace {
             return QVariant();
         }
     };
+    static_assert(std::is_pod<option_quintptr>::value, "option_quintptr must be a POD type.");
 
     typedef void (*qstring_set)(QString* val, const char* utf8, int nbytes);
     void set_qstring(QString* val, const char* utf8, int nbytes) {
diff --git a/tests/test_tree_rust.cpp b/tests/test_tree_rust.cpp
index 390c7d0..a823173 100644
--- a/tests/test_tree_rust.cpp
+++ b/tests/test_tree_rust.cpp
@@ -14,6 +14,7 @@ namespace {
             return QVariant();
         }
     };
+    static_assert(std::is_pod<option_quintptr>::value, "option_quintptr must be a POD type.");
 
     typedef void (*qstring_set)(QString* val, const char* utf8, int nbytes);
     void set_qstring(QString* val, const char* utf8, int nbytes) {