Convert hex to binary

[Steven Schveighoffer via Digitalmars-d-learn]

On 4/24/15 2:50 PM, nrgyzer wrote:
> On Friday, 24 April 2015 at 18:45:55 UTC, Jesse Phillips wrote:
>> On Friday, 24 April 2015 at 18:14:07 UTC, nrgyzer wrote:
>>> Hi,
>>>
>>> I'm looking for a function that converts my hex-string to a binary
>>> representation. In Python I write the following:
>>>
>>> myHex = "123456789ABCDEF"
>>> myBin = myHex.decode('hex')
>>>
>>> But how to do the same in D? Is there any function?
>>>
>>> Thanks for suggestions!
>>
>>     import std.stdio;
>>     void main(){
>>         import std.conv;
>>         import std.format;
>>
>>         auto i = to!ulong("123456789ABCDEF", 16);
>>
>>         writeln(format("%b", i));
>>     }
>
> Thanks to all of you for the solutions, but what if the hex-string
> exceeds the limit of ulong, for instance
> "123456789ABCDEF0123456789ABCDEF1234". How to convert them to a
> ulong-array?

Well, technically, a hex string can be split on 16-character boundaries, 
and then you could parse each one.

-Steve