Mixed language dll

[Kash]

I am trying to call a Fortran dll in my c++ code. The fortran bit is as follows: subroutine swap(x,y,z) real , intent(inout) :: x real , intent(inout) :: y real , intent(out) :: z real :: t ! !DEC$ATTRIBUTES dllexport :: swap !DEC$ATTRIBUTES DEFAULT, DECORATE, ALIAS: 'swap' :: swap ! t=x x=y y=t z=1.23 end subroutine swap <\code> The C++ calling code is: `#include using namespace std; extern "C" __declspec(dllimport)void swap(double &x, double &y,double &z); int main() { double x,y,z; x = 10; y = 999; swap(x,y,z); cout< There are some problems however. x and y are not swapped but they do display their original values on the console. And z has not been assigned a value. I think it's a problem with the C++ bit but I could be wrong. The good thing is that it compiles and executes. I will eventually try and do this in C# but one step at a time ;) Kash`

[David Crow]

Kash wrote: extern "C" __declspec(dllimport)void swap(double &x, double &y,double &z); Does Fortran support references? What happens if you change this to:

extern "C" __declspec(dllimport)void swap(double *x, double *y,double *z);
...
swap(&x, &y, &z);

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"One must learn from the bite of the fire to leave it alone." - Native American Proverb

[Tim Smith]

If that version of Fortran supports pointers, then it probably can support references indirectly. After all, under the hood, a reference is just a pointer without the dereferencing symantics. Tim Smith I'm going to patent thought. I have yet to see any prior art.