5 #ifndef KNOWROB_PREFIX_PROBE_H 
    6 #define KNOWROB_PREFIX_PROBE_H 
   11     struct PrefixProbe { std::string_view 
prefix; };
 
   12     bool operator<(PrefixProbe a, std::string_view b);
 
   13     bool operator<(std::string_view a, PrefixProbe b);
 
bool operator<(PrefixProbe a, std::string_view b)