You may find that reliability short-lived. I'm with ELISHEVA. The two formal ways of comparing floats/doubles are (coded in Perl, but same idea):
# absolute error method
$is_within_tolerance = abs($value - $expected) < EPSILON;

# relative error method - $tolerance_error should be within threshold 
+percentage
$tolerance_error = abs(($value - $expected) / $expected);

[download]

Crazy suggestion: You could write a function redofloat() that sprintf "%.15f" the number and then converts the resulting string back to a float/double. The idea here is to truncate each number's least significant bits that differ, caused by the division operations. Faster, if you can mask those bits off directly (but then you'd have to worry about portability).

Then: redofloat(foo) == redofloat(nv)

In reply to Re^5: [Win32, C, and way OT] C floats, doubles, and their equivalence by repellent
in thread [Win32, C, and way OT] C floats, doubles, and their equivalence by syphilis

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