ubytes to ulong problem

[Charles Hixson]

On 12/21/2013 02:31 PM, ponce wrote:
> On Saturday, 21 December 2013 at 22:29:59 UTC, ponce wrote:
>> On Saturday, 21 December 2013 at 22:22:09 UTC, Charles Hixson wrote:
>>> I was planning to ask if there were a better way to do this, but 
>>> instead I need to ask what's my mistake?
>>> For some reason, if called with an uninitialized ubyte array, and an 
>>> index of 0, it returns a value of 8, even though all the values in 
>>> the array are 0.
>>> The error has to be somewhere in the "ret = " statement, but I sure 
>>> don't see it.
>>>
>>> /**    Convert 8 consecutive bytes sliced from a ubyte[] into a ulong
>>> * @param    block    The array from which to slice.
>>> * @param    n    The starting index within the block    */
>>> ulong    ubytesToUlong(ubyte[] block, int n)
>>> {    ulong    ret;
>>>    assert (n >= 0);
>>>    assert (n + 8 <= block.length);
>>>    writefln ("n = %s", n);
>>>    writefln ("block[0] = %s", cast(ulong)block[0]);
>>>    writefln ("block[1] = %s", cast(ulong)block[1]);
>>>    writefln ("block[2] = %s", cast(ulong)block[2]);
>>>    writefln ("block[3] = %s", cast(ulong)block[3]);
>>>    writefln ("block[4] = %s", cast(ulong)block[4]);
>>>    writefln ("block[5] = %s", cast(ulong)block[5]);
>>>    writefln ("block[6] = %s", cast(ulong)block[6]);
>>>    writefln ("block[7] = %s", cast(ulong)block[7]);
>>>    ret    =    cast(ulong)block[n] * 2^21
>>>            +    cast(ulong)block[n+1] * 2^18
>>>            +    cast(ulong)block[n+2] * 2^15
>>>            +    cast(ulong)block[n+3] * 2^12
>>>            +    cast(ulong)block[n+4] * 2^9
>>>            +    cast(ulong)block[n+5] * 2^6
>>>            +    cast(ulong)block[n+6] * 2^3
>>>            +    cast(ulong)block[n+7] * 2^0;
>>>    writefln ("ret = %s", ret);
>>>    return    ret;
>>> }
>
> Use the exponentiation operator which is spelled: ^^
>
>
Thanks.  I was *sure* it was something stupid on my part.  It's 'good' 
to know that I was right about *that*.

-- 
Charles Hixson