#include "scan.h"

static const unsigned long maxlong = ((unsigned long)-1)>>1;

size_t scan_longlong(const char* src,signed long long* dest) {
  size_t i,o;
  unsigned long long l;
  char c=src[0];
  unsigned int neg=c=='-';
  o=c=='-' || c=='+';
  if ((i=scan_ulonglong(src+o,&l))) {
    if (i>0 && l>maxlong+neg) {
      l/=10;
      --i;
    }
    if (i+o) *dest=(signed long long)(c=='-'?-l:l);
    return i+o;
  } return 0;
}