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/errno.h"
  #include "libc/fmt/conv.h"
  #include "libc/fmt/strtol.internal.h"
  #include "libc/limits.h"
  #include "libc/str/str.h"
  
  /**
   * Decodes signed integer from wide string.
   *
   * @param s is a non-null nul-terminated string
   * @param endptr if non-null will always receive a pointer to the char
   *     following the last one this function processed, which is usually
   *     the NUL byte, or in the case of invalid strings, would point to
   *     the first invalid character
   * @param base can be anywhere between [2,36] or 0 to auto-detect based
   *     on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or
   *     decimal (base 10) by default
   * @return the decoded signed saturated number
   */
  long wcstol(const wchar_t *s, wchar_t **endptr, int base) {
    char t = 0;
    long x = 0;
    int d, c = *s;
    CONSUME_SPACES(s, c);
    GET_SIGN(s, c, d);
    GET_RADIX(s, c, base);
    if ((c = kBase36[c & 255]) && --c < base) {
      if (!((t |= 1) & 2)) {
        do {
          if (__builtin_mul_overflow(x, base, &x) ||
              __builtin_add_overflow(x, c * d, &x)) {
            x = d > 0 ? LONG_MAX : LONG_MIN;
            errno = ERANGE;
            t |= 2;
          }
        } while ((c = kBase36[*++s & 255]) && --c < base);
      }
    }
    if (t && endptr) *endptr = s;
    return x;
  }
  