Re: how to pass access string across pragma C interface?

[dewar@merv.cs.nyu.edu (Robert Dewar)]

David says

<<Assuming that the bit pattern for an access value and a C pointer are
identical on your
platform (this assumption is implicit in your interface pragma), then you
should
do something like:
buffer : string_access_type := new string (1 .. 2048);
>>


It is reasonable to assume that pointers to constrained array types are
easily mapped to C pointers, but it is asking for trouble to pass
pointers to unconstrained types. That is because the bounds information
must be somehow present, and C cannot know anything about it.

Thus code that passes such pointers to C, and even more code that receives
such pointers FROM C, is liable to be highly implementation dependent.