In releases before 2010a, literal numbers inside int64() and uint64() calls were understood by MATLAB as meaning to parse the numbers as class double and to call the int64() or uint64() method on the resulting double. For example,
>> uint64(18446744073709551600) ans = 18446744073709551615
Starting with release 2010a, the literal numbers are instead fully valued at parse time and given appropriate type.
I do not have R2010a or later available, so I would ask that people investigate the limits of that parsing in the new versions and report back.
For example:
And more generally, is there any expression X whose absolute value does not exceed 2^53, for which
B = int64(X);
is not the same as
A = X; B = uint64(A);
?
Hi,
tested with R2011a 64bit on Win7:
>> int64(18446744073709551600)
ans =
9223372036854775807
>> uint64(18446744073709551600+0)
ans =
18446744073709551615
>> uint64(18446744073709551600*1)
ans =
18446744073709551615
>> uint64(+18446744073709551600)
ans =
18446744073709551615
>> uint64(18446744073709551600.)
ans =
18446744073709551615
>> uint64(18446744073709551600.1)
ans =
18446744073709551615
>> uint64(18446744073709551600e0)
ans =
18446744073709551615
>> int64(2^64-15)
ans =
9223372036854775807
>> uint64(18446744073709551600/2)
ans =
9223372036854775808
>> uint64(9223372036854775800)
ans =
9223372036854775800
Hi,
sorry but I don't get your second part with the unary plus and minus. Could you please explain to me what I have to do?
int64(-9223372036854775808)
ans =
-9223372036854775808
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