On Mon, Mar 12, 2018 at 01:04:06AM +0000, Joe via Digitalmars-d-learn wrote: > On Sunday, 11 March 2018 at 23:26:04 UTC, Stefan Koch wrote: > > You have to pass a pointer to the function. > > Otherwise it'll be a parenthsis-less call. > > use : qsort(recs, num_recs, (Record *).sizeof, &compar); > > After passing a pointer, getting some other error messages, I changed > the call to > > qsort(cast(void *)recs, num_recs, cast(size_t)(Record *).sizeof, > &compar); > > and the latest error is: > > Error: function core.stdc.stdlib.qsort (scope void* base, ulong nmemb, ulong > size, extern (C) int function(scope const(void*), scope const(void*)) > @system compar) is not callable using argument types (void*, ulong, ulong, > int function(const(void*) p1, const(void*) p2)) > > I fail to see which argument is causing the problem now. [...]
I wonder if the problem is because qsort expects a C linkage function (`extern (C) int function(...)`), but you're passing a D linkage (i.e., native) function to it. You can't do that, because the order of arguments in a D linkage function may differ from a C linkage function, and could potentially cause a subtle bug if you're not expecting the arguments in a different order. (I actually ran into this myself, in a different context where there was no type enforcement like there is here, and it took me a long time to track down the problem.) If indeed this is the problem, try adding `extern (C)` to your D function to make it compatible with C linkage, and that should do the trick. I think. T -- If you look at a thing nine hundred and ninety-nine times, you are perfectly safe; if you look at it the thousandth time, you are in frightful danger of seeing it for the first time. -- G. K. Chesterton
