Returns a newFloat object having approximately the same value as
the BigDecimal number. Normal accuracy limits and built-in
errors of binary Float arithmetic apply.
static VALUE
BigDecimal_to_f(VALUE self)
{
ENTER(1);
Real *p;
double d;
SIGNED_VALUE e;
char *buf;
volatile VALUE str;
GUARD_OBJ(p, GetVpValue(self, 1));
if (VpVtoD(&d, &e, p) != 1)
return rb_float_new(d);
if (e > (SIGNED_VALUE)(DBL_MAX_10_EXP+BASE_FIG))
goto overflow;
if (e < (SIGNED_VALUE)(DBL_MIN_10_EXP-BASE_FIG))
goto underflow;
str = rb_str_new(0, VpNumOfChars(p, "E"));
buf = RSTRING_PTR(str);
VpToString(p, buf, 0, 0);
errno = 0;
d = strtod(buf, 0);
if (errno == ERANGE) {
if (d == 0.0) goto underflow;
if (fabs(d) >= HUGE_VAL) goto overflow;
}
return rb_float_new(d);
overflow:
VpException(VP_EXCEPTION_OVERFLOW, "BigDecimal to Float conversion", 0);
if (p->sign >= 0)
return rb_float_new(VpGetDoublePosInf());
else
return rb_float_new(VpGetDoubleNegInf());
underflow:
VpException(VP_EXCEPTION_UNDERFLOW, "BigDecimal to Float conversion", 0);
if (p->sign >= 0)
return rb_float_new(0.0);
else
return rb_float_new(-0.0);
}