Basics of calling C from D

[Adam D. Ruppe via Digitalmars-d-learn]

On Wednesday, 11 June 2014 at 13:52:09 UTC, belkin wrote:
> Question: How do I use it from D?

Write the prototype in your D file with extern(C):
extern(C) int factorial(int n);

then just call the function normally in D. Make sure you include 
all the C object files when you compile the D program too so it 
all links together.