I'm trying to wrap the Parma Polyhedron Library in Julia.
The library itself is written in C++, I am trying to wrap the C API.
Consider a snippet of an C example which uses the C API
static int
solve_with_generators(ppl_Constraint_System_t ppl_cs,
ppl_const_Linear_Expression_t ppl_objective_le,
ppl_Coefficient_t optimum_n,
ppl_Coefficient_t optimum_d,
ppl_Generator_t point) {
ppl_Polyhedron_t ppl_ph;
...
/* Create the polyhedron (recycling the data structures of ppl_cs). */
ppl_new_C_Polyhedron_recycle_Constraint_System(&ppl_ph, ppl_cs);
To illustrate my problem, consider the call to*
ppl_new_C_Polyhedron_recycle_Constraint_System* which creates a constraint
system, and has signature:
ppl_new_C_Polyhedron_recycle_Constraint_System(ppl_Polyhedron_t* pph,
ppl_Constraint_System_t cs)
*ppl_Polyhedron_*t is typedef generated using macros, but effectively it is
defined by
typedef struct ppl_Polyhedron_tag* ppl_Polyhedron_t;
I can't find anywhere in the source where these structs are defined, but
presumably they must (my C is very rusty). In any case, the problem is
that from Julia I don't have access to these typedefs. If I want to ccall
*ppl_new_C_Polyhedron_recycle_Constraint_System*, what can I use as the
first and second arguments? My (currently very naive) intuition is that I
need C functions which return values of the type *ppl_Polyhedron_t* for
instance, but it seems this API does not follow that pattern. Is this
correct? Will I need to do something like write another C API which just
returns pointers? Or is there a simpler solution?
Thanks
