FFI, safe vs unsafe

[Claus Reinke]

>This is the way it is right now in GHC: the default is "safe", and safe
>means both reentrant and concurrent.  This is for the reason you give:
>the default should be the safest, in some sense.
>..
>So we can't have the default (unanotated) foreign call be something that
>isn't required by the standard. 

why not? you'd only need to make sure that in standard mode,
no unannotated foreign declarations are accepted (or that a warning
is given).

claus