It's the same in C and it reflects what the hardware is doing underneath with regard to memory addresses. That's the point of size_t. If it didn't change size then we'd all just use ulong or uint for all our array lengths etc.
In c#,add the new attribute 'longlength' on the new version,keep the ‘length' in the attributes,and the type 'int' or 'uint' that is ok for most of condition ,maybe a longlength is ok for a little condition.
Thank you. Frank
