message: Remove key_equal
diff: @@ -147,19 +147,7 @@ protected:
  + 8 * (int)std::get<3>(k);
  }
  };
  - struct key_equal
  - {
  - bool operator()(const key_face& v0, const key_face& v1) const
  - {
  - return (
  - std::get<0>(v0) == std::get<0>(v1) &&
  - std::get<1>(v0) == std::get<1>(v1) &&
  - std::get<2>(v0) == std::get<2>(v1) &&
  - std::get<3>(v0) == std::get<3>(v1)
  - );
  - }
  - };
  - using map_L2F = std::unordered_map<const key_face,Operator*,key_hash,key_equal>;
  + using map_L2F = std::unordered_map<const key_face,Operator*,key_hash>;
  mutable map_L2F L2F;
  mutable Array<QuadratureInterpolator*> E2Q_array;
  