On Wednesday, 3 February 2016 at 04:19:37 UTC, jmh530 wrote:
A few extra questions: 1) In other parts of the code I'm using extern(System), but that doesn't work for these. Why is extern(C) used for function pointers?,
extern(C) is only used with function pointers when it's needed. It depends entirely on how the C library was compiled. By default, most compilers compile with the cdecl calling convention, which is what extern(C) specifies in D code. Windows system libraries are usually compiled to use the stdcall calling convention. The D equivalent is extern(Windows). extern(System) translates to extern(Windows) on Windows and extern(C) elsewhere. Function pointers passed to C code need to have the same calling convention as that of the library to which they are passed.
2) You use const(double)*, in other parts of the code I had converted the C code from const char* to const(char*). Does it matter where the pointer * falls?
Technically, const(char)* is a mutable pointer to const data and const(char*) is an immutable pointer to const data.
