d

Does D have 'newtype' (as in Haskell). It's a naive question, as I'm just skimming D, but Google didn't turn up anything useful. In Haskell this is a way of making different types of the same thing distinct at compile time, but without incurring any runtime performance penalties. e.g. you could make newtypes (doubles) for metres, seconds and kilograms. This would error at compile time if your program added a quantity in metres to a quantity in seconds, but would be just as fast at runtime as if both were doubles (which they are at runtime). If D doesn't have something analogous to 'newtype',

Today I heard about the D programming and that it is compatible to C code. Nevertheless I haven't found any information on whether it is possible to use C libraries like GTK or PortAudio from D? If it is possible, could you explain how to do this? It is possible to call C libraries from D. What you need to do is to convert the C header files to D. For the most part this is pretty straightforward, and there is a hard-to-use command-line tool to help automate the process. It's never really worked for me on anything but toy examples, but it could be a good start to see the kind of transformations

I'm new to D, and I'm looking for a good way to program with Haskell-like type classes e.g. Functors, Monoids, etc. in D. Is something like this implemented in Tango or Phobos? I've heard about traits which enable compile-time type checking for certain properties. Can they be used for type classes? I've tried a little bit with template specialization and come up with this: // Monoid.d // generic Monoid gets called when there is no instance of Monoid for Type T class Monoid(T) { pragma(msg, "Type is not a Monoid"); } // Monoid instance for double class Monoid(T:double) { static T mzero() {

I've always wondered: isn't ptrdiff_t supposed to be able to hold the difference of any two pointers by definition ? How come it fails when the two pointers are too far? (I'm not pointing at any particular language... I'm referring to all languages which have this type.) (e.g. subtract the pointer with address 1 from the byte pointer with address 0xFFFFFFFF when you have 32-bit pointers, and it overflows the sign bit...) No, it is not. $5.7 [expr.add] (from n3225 - C++0x FCD) When two pointers to elements of the same array object are subtracted, the result is the difference of the subscripts

Is there a way to dynamically load and call functions from DLLs dynamically in D? I'd like my program to be able to load plugins at startup and perhaps on-the-fly as well. It depends on how dynamic you want to get. If you want to dynamically load a dll and run some predefined functions, there is a very nice wrapper by Wei Li here . Thanks to the power of templates, it allows you to do things like these: // define functions alias Symbol!("MessageBoxW", int function(HWND, LPCWSTR, LPCWSTR, UINT)) mbw; alias Symbol!("MessageBoxA", int function(HWND, LPCSTR, LPCSTR, UINT)) mba; // load dll auto