[julia-users] Voronoi tess / ccall with Fortran

[Lutfullah Tomak]

I think you already know Fortran functions take arguments by reference/pointer. 
If there is not a typo in ccall some of the arguments are not Ptr but IntXX in 
the example. I suggest you use Ref instead of Ptr and just pass any variable 
since it will be converted automatically to a pointer. You can use Ref if you 
are in julia 0.4+. Warning suggest you use unsafe_convert since casting an 
integer a pointer is unsafe(I think).
Reference to ccall and Ref
http://docs.julialang.org/en/release-0.4/manual/calling-c-and-fortran-code/