Integer conversions too pedantic in 64-bit

[Don]

Walter Bright wrote:
> Don wrote:
>> [1] What was size_t on the 286 ?

> 
> 16 bits
> 
>> Note that in the small memory model (all pointers 16 bits) it really 
>> was possible to have an object of size 0xFFFF_FFFF, because the code 
>> was in a different address space.
> 
> Not really. I think the 286 had a hard limit of 16 Mb.

I mean, you can have a 16 bit code pointer, and a 16 bit data pointer. 
So, you can concievably have a 64K data item, using the full size of size_t.
That isn't possible on a modern, linear address space, because the code 
has to go somewhere...

> 
> There was a so-called "huge" memory model which attempted (badly) to 
> fake a linear address space across the segmented model. It never worked 
> very well (such as having wacky problems when an object straddled a 
> segment boundary), and applications built with it sucked in the 
> performance dept. I never supported it for that reason.
> 
> A lot of the effort in 16 bit programming went to breaking up data 
> structures so no individual part of it spanned more than 64K.

Yuck.
I just caught the very last of that era. I wrote a couple of 16-bit 
DLLs. From memory, you couldn't assume the stack was in the data 
segment, and you got horrific memory corruption if you did.
I've got no nostalgia for those days...