Don't write platform datatype size table in template mode

Author: franzpoeschel

src/IO/JSON/JSONIOHandlerImpl.cpp

@@ -1319,7 +1319,16 @@ void JSONIOHandlerImpl::putJsonContents(
     if (it != m_jsonVals.end())
     {
         auto fh = getFilehandle(filename, Access::CREATE);
-        (*it->second)["platform_byte_widths"] = platformSpecifics();
+
+        switch (m_mode)
+        {
+        case IOMode::Dataset:
+            (*it->second)["platform_byte_widths"] = platformSpecifics();
+            break;
+        case IOMode::Template:
+            break;
+        }
+
         switch (m_fileFormat)
         {
         case FileFormat::Json:
@@ -1329,6 +1338,7 @@ void JSONIOHandlerImpl::putJsonContents(
             *fh << openPMD::json::jsonToToml(*it->second) << std::endl;
             break;
         }
+
         VERIFY(fh->good(), "[JSON] Failed writing data to disk.")
         m_jsonVals.erase(it);
         if (unsetDirty)