Default item names #209

Technically should not be needed - but MP2NL's subsolvers sometimes don't use original names TODO

include/mp/nl-reader.h

@@ -2531,7 +2531,7 @@ class NameProvider {
 
 private:
   std::vector<const char *> names_;
-  std::string gen_name_, gen_name_2_;
+  std::string gen_name_ {"_std_"}, gen_name_2_ {"_extra_"};
   internal::NameReader reader_;
   fmt::MemoryWriter writer_;
 };