next power of 2

[Dmitry Olshansky]

On 07-Oct-12 00:58, Andrei Alexandrescu wrote:
> On 10/6/12 4:57 PM, Dmitry Olshansky wrote:
>> On 07-Oct-12 00:54, Dmitry Olshansky wrote:
>>> On 07-Oct-12 00:48, ref2401 wrote:
>>>> is there any Phobos function to calculate the next power of 2 of the
>>>> specified number?
>>>
>>> No though it's reinvented in a couple of places I think.
>>>
>>> Anyway this should work for unsigned numbers:
>>>
>>> import core.bitop;
>>> T nextPow2(T)(T x){
>>> return x == 0 ? 1 : 1^^(bsr(x)+1);
>>> }
>>
>> Yikes, 1<<(bsr(x)+1) or 2 ^^ (bsr(x)+1) ...
>> still haven't got used to 2^^x notation compared to shifts.
>
> That's right, apologies for my buggy suggestion and my suggestion of a
> buggy suggestion :o).
>

Post of the day :)

-- 
Dmitry Olshansky