strcspn -> strchr when only 1 delimiter

[yakra]

strcspn takes up time, however little, looping thru an array and checking whether within bounds. Why not skip the looping when we won't need an array?

• [ ] Will something like this work?

  for (size_t spn = 0; *c; c += spn)
  { for (spn = strcspn(c, " "); c[spn] == ' '; spn++) c[spn] = 0;
  alt_labels.emplace_back(c);
  }

  ->

  for (char* d; *c; c = d)
  { for (d = strcchr(c, ' '); *d == ' '; d++) *d = 0;
  alt_labels.emplace_back(c);
  }

• [ ] Not just AltLabel construction, but everywhere strcspn is used.

[yakra]

Won't work. If delimiter (space in this example) is not found, d is set to 0. And then we try to dereference it. Having to check whether d is valid (and then potentially do whatever) outweighs the benefit of losing the bounds checking.

[yakra]

Wait, how about something like this?

// label
char* c = strchr(line, ' ');
if (c)  do *c = 0; while (*++c == ' ');
else    /* not important in this example */ ;
label = line;