What is the FreeBSD situation?

[Walter Bright]

On 11/2/2017 2:25 PM, Jonathan M Davis wrote:
> On Thursday, November 02, 2017 13:46:11 Walter Bright via Digitalmars-d
> wrote:
>> On 11/1/2017 10:11 PM, Jonathan M Davis wrote:
>>> But we
>>> don't currently have a way to version code for a particular version of
>>> FreeBSD even if we wanted to.
>>
>> The FreeBSD version can be detected at runtime, and different code
>> executed.
> 
> Sure, but you can't actually compile different code based on the FreeBSD
> version, and if a type or function API changes, then that doesn't work.
> Wouldn't you get a linker error for the stuff that isn't actually defined on
> the C side of things? If so, then you can't really provide both the old and
> new versions of a function or type and switch between code that uses one or
> the other based on the version of the OS at runtime. You'd have to be able
> to have the source code differ depending on the FreeBSD version.

I know in Windows the imports can be dynamically loaded at runtime.