More C standard functions

[adriweb]

These could be useful, though I'm not sure where to put them, so I'll let someone who knows take care of that :P

char* strndup(const char* s, size_t n)
{
  char* result;
  size_t len = strlen(s);

  if (n < len) {
    len = n;
  }

  result = (char*)malloc(len + 1);
  if (!result) {
    return NULL;
  }

  result[len] = '\0';
  return (char*)memcpy(result, s, len);
}

double round(double x) {
    return (x >= 0.0) ? floor(x + 0.5) : ceil(x - 0.5);
}

I'm not so sure about that one (well, it doesn't handle all cases...), but it's fine for most.

Other additions that would be nice: log2, tgamma.