text: // ======================================================================== //
  // Copyright 2009-2018 Intel Corporation                                    //
  //                                                                          //
  // Licensed under the Apache License, Version 2.0 (the "License");          //
  // you may not use this file except in compliance with the License.         //
  // You may obtain a copy of the License at                                  //
  //                                                                          //
  //     http://www.apache.org/licenses/LICENSE-2.0                           //
  //                                                                          //
  // Unless required by applicable law or agreed to in writing, software      //
  // distributed under the License is distributed on an "AS IS" BASIS,        //
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. //
  // See the License for the specific language governing permissions and      //
  // limitations under the License.                                           //
  // ======================================================================== //
  
  #pragma once
  
  #include "parallel_sort.h"
  
  namespace embree
  {
    /* implementation of a set of values with parallel construction */
    template<typename T>
    class parallel_set
    {
    public:
  
      /*! default constructor for the parallel set */
      parallel_set () {}
  
      /*! construction from vector */
      template<typename Vector>
        parallel_set (const Vector& in) { init(in); }
  
      /*! initialized the parallel set from a vector */
      template<typename Vector>
        void init(const Vector& in) 
      {
        /* copy data to internal vector */
        vec.resize(in.size());
        parallel_for( size_t(0), in.size(), size_t(4*4096), [&](const range<size_t>& r) {
  	for (size_t i=r.begin(); i<r.end(); i++) 
  	  vec[i] = in[i];
        });
  
        /* sort the data */
        std::vector<T> temp(in.size());
        radix_sort<T>(vec.data(),temp.data(),vec.size());
      }
  
      /*! tests if some element is in the set */
      __forceinline bool lookup(const T& elt) const {
        return std::binary_search(vec.begin(), vec.end(), elt);
      }
  
      /*! clears all state */
      void clear() {
        vec.clear();
      }
  
    private:
      std::vector<T> vec;   //!< vector containing sorted elements
    };
  }
  