On Tuesday, 2 February 2016 at 22:56:28 UTC, jmh530 wrote:
My D code calls a C function. One of the parameters to the C
function is a function pointer to a D function. This D function
(below) is one that I copied from the C library's tutorial. I
only slightly changed the signature. This function is
eventually called in other functions in the C library.
double myfunc(uint n, const double* x, double* grad, void*
my_func_data)
Thus, as it is an Access Violation, I'm guessing the issue is
with accessing elements of arrays in the D function from the C
function. I don't know. When I try to call the D function in D,
it works, but I have to refer to x and grad as x.ptr and
grad.ptr.
I'm not sure how to go about fixing this...
The parameter to the C function should be declared as extern(C),
and so should your function implementation.
extern(C) alias FuncPtr = double function(uint, const(double)*,
double*, void*);
extern(C) void takeFuncPtr(FuncPtr);
extern(C) double myfunc(uint n, const(double)* x, double* grad,
void* my_func_data) {
...
}
If you haven't done that, then this is quite possibly the root of
your problem.
