AJ Wrote:
>
> How can/does D guarantee that "int" will always be 32 bits on all platforms? Does this mean that D won't work on some platforms? Why is integer width so ambiguous in C/C++? (I am using "platform" as equivalent to CPU+OS+compiler).

int can be any width D wants it to be and everything works great so long as you're only calling D functions.  The conflict comes when calling C functions, and there's nothing in the language for addressing this.  Instead, it's a library issue.  For example, Druntime's core.stdc.config defines "c_long" and "c_ulong" types for interfacing with C, since these types change width across 32 and 64-bit platforms.  There's been no attempt to deal with odd-sized int or other types though.  That just isn't an issue on common platforms.

"Sean Kelly" <sean@invisibleduck.org> wrote in message news:hbo3bv$2q25$1@digitalmars.com...
> AJ Wrote:
>>
>> How can/does D guarantee that "int" will always be 32 bits on all
>> platforms?
>> Does this mean that D won't work on some platforms? Why is integer width
>> so
>> ambiguous in C/C++? (I am using "platform" as equivalent to
>> CPU+OS+compiler).
>
> int can be any width D wants it to be and everything works great so long as you're only calling D functions.  The conflict comes when calling C functions, and there's nothing in the language for addressing this. Instead, it's a library issue.  For example, Druntime's core.stdc.config defines "c_long" and "c_ulong" types for interfacing with C, since these types change width across 32 and 64-bit platforms.  There's been no attempt to deal with odd-sized int or other types though.  That just isn't an issue on common platforms.

I had struct layout/size/alignment/member-alignment concerns.