// See www.openfst.org for extensive documentation on this weighted
  // finite-state transducer library.
  
  #ifndef FST_SCRIPT_DIFFERENCE_H_
  #define FST_SCRIPT_DIFFERENCE_H_
  
  #include <tuple>
  
  #include <fst/difference.h>
  #include <fst/script/compose.h>
  #include <fst/script/fst-class.h>
  
  namespace fst {
  namespace script {
  
  using DifferenceArgs = std::tuple<const FstClass &, const FstClass &,
                                    MutableFstClass *, const ComposeOptions &>;
  
  template <class Arc>
  void Difference(DifferenceArgs *args) {
    const Fst<Arc> &ifst1 = *(std::get<0>(*args).GetFst<Arc>());
    const Fst<Arc> &ifst2 = *(std::get<1>(*args).GetFst<Arc>());
    MutableFst<Arc> *ofst = std::get<2>(*args)->GetMutableFst<Arc>();
    const auto &opts = std::get<3>(*args);
    Difference(ifst1, ifst2, ofst, opts);
  }
  
  void Difference(const FstClass &ifst1, const FstClass &ifst2,
                  MutableFstClass *ofst,
                  const ComposeOptions &opts = ComposeOptions());
  
  }  // namespace script
  }  // namespace fst
  
  #endif  // FST_SCRIPT_DIFFERENCE_H_