Question

Is C# ever Endian sensitive, for example, will code such as this:

int a = 1234567;
short b = *(short*)&i;

always assign the same value to b. If so, what value will it be?

If not, what good ways are there to deal with endianness if code with pointers in?

Answer 1

C# doesn’t define the endianness. In reality, yes it will probably always be little-endian (IIRC even on IA64, but I haven’t checked), but you should ideally check BitConverter.IsLittleEndian if endianness is important – or just use bit-shifting etc rather than direct memory access.

To quote a few lines from protobuf-net (a build not yet committed):

WriteInt64(*(long*)&value);
if (!BitConverter.IsLittleEndian)
{   // not fully tested, but this *should* work
    Reverse(ioBuffer, ioIndex - 8, 8);
}

i.e. it checks the endianness and does a flip if necessary.