GNU/Linux compatibility

[HatCat]

The second option sounds simple enough. If matters on the branch weighing are handled appropriately, checking if the address is invalid should be a very miniscule cut by assuming that the validity of the address is by far the most likely branch case. However the Microsoft compiler seems to override that concept at times.

I have no idea what SEH is.

The third option would be the sexiest. Function-oriented templating is always a bit more 1:1 translatable to the human concept, but I would always avoid laying a series out except for cases where the conditional operations were too large or too complex to maintain in the local scope.

Also, I think that writing any code for portability, is a plus anywhere, not just GNU/Linux.
Linux would be a prime example for targeting portability, but keeping code simplicity and purity as a general rule of thumb should suffice over the need of targeting any default operating system.