Byte Order Swapping Function

[Andrei Alexandrescu]

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