text: /*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
  │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
  ╞══════════════════════════════════════════════════════════════════════════════╡
  │ Copyright 2020 Justine Alexandra Roberts Tunney                              │
  │                                                                              │
  │ Permission to use, copy, modify, and/or distribute this software for         │
  │ any purpose with or without fee is hereby granted, provided that the         │
  │ above copyright notice and this permission notice appear in all copies.      │
  │                                                                              │
  │ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
  │ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
  │ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
  │ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
  │ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
  │ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
  │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
  │ PERFORMANCE OF THIS SOFTWARE.                                                │
  ╚─────────────────────────────────────────────────────────────────────────────*/
  #include "libc/alg/alg.h"
  #include "libc/bits/bits.h"
  #include "libc/macros.h"
  #include "libc/mem/mem.h"
  #include "libc/str/str.h"
  #include "libc/testlib/testlib.h"
  
  TEST(qsort, test) {
    const int32_t A[][2] = {{4, 'a'},   {65, 'b'}, {2, 'c'}, {-31, 'd'},
                            {0, 'e'},   {99, 'f'}, {2, 'g'}, {83, 'h'},
                            {782, 'i'}, {1, 'j'}};
    const int32_t B[][2] = {{-31, 'd'}, {0, 'e'},  {1, 'j'},  {2, 'c'},
                            {2, 'g'},   {4, 'a'},  {65, 'b'}, {83, 'h'},
                            {99, 'f'},  {782, 'i'}};
    int32_t(*M)[2] = malloc(sizeof(A));
    memcpy(M, B, sizeof(A));
    qsort(M, ARRAYLEN(A), sizeof(*M), cmpsl);
    EXPECT_EQ(0, memcmp(M, B, sizeof(B)));
    free(M);
  }
  