//===----------------------------------------------------------------------===//
//
// 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 gslice_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};
    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};
    std::valarray<int> v1(a1, sizeof(a1)/sizeof(a1[0]));
    std::valarray<int> v2(a2, sizeof(a2)/sizeof(a2[0]));
    std::size_t sz[] = {2, 4, 3};
    std::size_t st[] = {19, 4, 1};
    typedef std::valarray<std::size_t> sizes;
    typedef std::valarray<std::size_t> strides;
    v1[std::gslice(3, sizes(sz, sizeof(sz)/sizeof(sz[0])),
                      strides(st, sizeof(st)/sizeof(st[0])))] <<= v2;
    assert(v1.size() == 41);
    assert(v1[ 0] ==  0);
    assert(v1[ 1] ==  1);
    assert(v1[ 2] ==  2);
    assert(v1[ 3] ==  6);
    assert(v1[ 4] == 16);
    assert(v1[ 5] == 40);
    assert(v1[ 6] ==  6);
    assert(v1[ 7] == 112);
    assert(v1[ 8] == 256);
    assert(v1[ 9] == 576);
    assert(v1[10] == 10);
    assert(v1[11] == 1408);
    assert(v1[12] == 3072);
    assert(v1[13] == 6656);
    assert(v1[14] == 14);
    assert(v1[15] == 15360);
    assert(v1[16] == 32768);
    assert(v1[17] == 69632);
    assert(v1[18] == 18);
    assert(v1[19] == 19);
    assert(v1[20] == 20);
    assert(v1[21] == 21);
    assert(v1[22] == 180224);
    assert(v1[23] == 376832);
    assert(v1[24] == 786432);
    assert(v1[25] == 25);
    assert(v1[26] == 1703936);
    assert(v1[27] == 3538944);
    assert(v1[28] == 7340032);
    assert(v1[29] == 29);
    assert(v1[30] == 15728640);
    assert(v1[31] == 32505856);
    assert(v1[32] == 67108864);
    assert(v1[33] == 33);
    assert(v1[34] == 142606336);
    assert(v1[35] == 293601280);
    assert(v1[36] == 603979776);
    assert(v1[37] == 37);
    assert(v1[38] == 38);
    assert(v1[39] == 39);
    assert(v1[40] == 40);

  return 0;
}