text: //===----------------------------------------------------------------------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  
  // <valarray>
  
  // template <class T> class indirect_array
  
  // void operator>>=(const valarray<value_type>& v) const;
  
  #include <valarray>
  #include <cassert>
  
  int main(int, char**)
  {
      int a1[] = { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11,
                  12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,
                  24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
                  36, 37, 38, 39, 40};
      const std::size_t N1 = sizeof(a1)/sizeof(a1[0]);
      int a2[] = {  1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11, 12,
                   13,  14,  15,  16,  17,  18,  19,  20,  21,  22,  23, 24};
      const std::size_t N2 = sizeof(a2)/sizeof(a2[0]);
      std::size_t s[N2] = { 3,  4,  5,  7,  8,  9, 11, 12, 13, 15, 16, 17,
                           22, 23, 24, 26, 27, 28, 30, 31, 32, 34, 35, 36};
      std::valarray<int> v1(a1, N1);
      std::valarray<int> v2(a2, N2);
      std::valarray<std::size_t> ia(s, N2);
      v1[ia] >>= v2;
      assert(v1.size() == 41);
      assert(v1[ 0] ==  0);
      assert(v1[ 1] ==  1);
      assert(v1[ 2] ==  2);
      assert(v1[ 3] ==  1);
      assert(v1[ 4] ==  1);
      assert(v1[ 5] ==  0);
      assert(v1[ 6] ==  6);
      assert(v1[ 7] ==  0);
      assert(v1[ 8] ==  0);
      assert(v1[ 9] ==  0);
      assert(v1[10] == 10);
      assert(v1[11] ==  0);
      assert(v1[12] ==  0);
      assert(v1[13] ==  0);
      assert(v1[14] == 14);
      assert(v1[15] ==  0);
      assert(v1[16] ==  0);
      assert(v1[17] ==  0);
      assert(v1[18] == 18);
      assert(v1[19] == 19);
      assert(v1[20] == 20);
      assert(v1[21] == 21);
      assert(v1[22] ==  0);
      assert(v1[23] ==  0);
      assert(v1[24] ==  0);
      assert(v1[25] == 25);
      assert(v1[26] ==  0);
      assert(v1[27] ==  0);
      assert(v1[28] ==  0);
      assert(v1[29] == 29);
      assert(v1[30] ==  0);
      assert(v1[31] ==  0);
      assert(v1[32] ==  0);
      assert(v1[33] == 33);
      assert(v1[34] ==  0);
      assert(v1[35] ==  0);
      assert(v1[36] ==  0);
      assert(v1[37] == 37);
      assert(v1[38] == 38);
      assert(v1[39] == 39);
      assert(v1[40] == 40);
  
    return 0;
  }
  