ruby/missing/isinf.c

47 строки
709 B
C

/* public domain rewrite of isinf(3) */
#ifdef __osf__
#define _IEEE 1
#include <nan.h>
int
isinf(n)
double n;
{
if (IsNANorINF(n) && IsINF(n)) {
return 1;
} else {
return 0;
}
}
#else
#include "config.h"
#ifdef HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
#endif
static double zero() { return 0.0; }
static double one() { return 1.0; }
static double inf() { return one() / zero(); }
int
isinf(n)
double n;
{
static double pinf = 0.0;
static double ninf = 0.0;
if (pinf == 0.0) {
pinf = inf();
ninf = -pinf;
}
return memcmp(&n, &pinf, sizeof n) == 0
|| memcmp(&n, &ninf, sizeof n) == 0;
}
#endif