Byte Order Swapping Function

Christian Manning cmanning999 at gmail.com
Fri Jul 15 14:23:01 PDT 2011


Andrei Alexandrescu wrote:

> On 7/14/11 5:51 AM, Regan Heath wrote:
>> That's my point. I need 8/16/32/64/128 bit versions and it really would
>> be better if there were general variants. My version are less than
>> optimal, but do use intrinsics where possible. Someone else can do a far
>> better job than I, and it really should be done once, by that person.
>> Surely we have the infrastructure for someone to add this to phobos? If
>> something this simple can't or won't be done, what hope do we have!?
> 
> I think we should have these functions in std.bitmanip:
> 
> T toBigEndian(T)(T val) if (isArithmetic!T || isSomeChar!T);
> T toLittleEndian(T)(T val) if (isArithmetic!T || isSomeChar!T);
> T bigEndianToNative(T)(T val) if (isArithmetic!T || isSomeChar!T);
> T littleEndianToNative(T)(T val) if (isArithmetic!T || isSomeChar!T);
> 
> That means all characters, all integers, and all floating point numbers.
> The implementations would opportunistically use intrinsics and other
> specialized means.
> 
> The documentation should specify the relationship to htonl and ntohl.
> 
> If there's a need for converting endianness of larger buffers, we might
> add:
> 
> ubyte[] toBigEndian(ubyte[] val);
> ubyte[] toLittleEndian(ubyte[] val);
> ubyte[] bigEndianToNative(ubyte[] val);
> ubyte[] littleEndianToNative(ubyte[] val);
> 
> They'd use std.algorithm.reverse internally as needed.
> 
> It's a sweet piece of work. Anyone have the time to prepare a pull
> request?
> 
> 
> Andrei

Am I being naïve in thinking I can just do this: 
alias littleEndianToNative toLittleEndian;
alias bigEndianToNative toBigEndian;
?

Chris


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