/*
 *  call-seq:
 *     flt.nan? -> true or false
 *
 *  Returns <code>true</code> if <i>flt</i> is an invalid IEEE floating
 *  point number.
 *
 *     a = -1.0      #=> -1.0
 *     a.nan?        #=> false
 *     a = 0.0/0.0   #=> NaN
 *     a.nan?        #=> true
 */

static VALUE
flo_is_nan_p(VALUE num)
{
    double value = RFLOAT_VALUE(num);

    return isnan(value) ? Qtrue : Qfalse;
}