The speed depends on the TLS implementation. Yes, you are correct that TLS can be as fast as a pointer lookup. It can even be faster on systems with a memory management unit. For the pointer lookup you need help from the scheduler though. The scheduler must – on a task switch – update the … Read more
Sure, you can detect pure functions in some cases. For instance, int f(int x) { return x*2; } can be detected as pure with simple static analysis. The difficulty is doing this in general, and detecting interfaces which use “internal” state but are externally pure is basically impossible. GCC does have the warning options -Wsuggest-attribute=pure … Read more
D can use pretty much any C library, just define the functions needed. D can also use C++ libraries, but D does not understand certain C++ constructs. So… D can use almost as many libraries as C++. They just aren’t native D libs. From D’s Library reference. Core.memory: static nothrow void disable(); Disables automatic garbage … Read more
Version 1 of D is mature and stable, and there are definitely folks who use it for real work. Phobos is the only standard library that D has ever had or likely ever will have, but D1’s Phobos is lacking enough that various third-party libraries were created to fill in the gaps. Tango is the … Read more
You can define an on-load function for a linux library using the .init mechanism. This is the same as specifying the load-time entry point for a binary (e.g. using something other than main as the entry point for a program). When linking using ld directly you use the: -init <function name> or if you’re using … Read more
I used D 1.x for doing games and demos, some of them are public domain open source (A, B, C, D, E). D can give you productivity unheard of in C++-land if you are willing to pay the high-price of arguing with everyone about why do you use D. If you go this route, i … Read more
DMD is the reference implementation, the backend and frontend are open source. The code generation quality is not that overwhelming. GDC and LDC are both based on the DMD frontend so it might take some time until a new version of the frontend is merged in. Since the backends they use are very mature and … Read more
Being context free is first a property of generative grammars. It means that what a non-terminal can generate will not depend on the context in which the non-terminal appears (in non context-free generative grammar, the very notion of “string generated by a given non-terminal” is in general difficult to define). This doesn’t prevent the same … Read more
The two biggest things that help template metaprogramming in D are template constraints and static if – both of which C++ could theoretically add and which would benefit it greatly. Template constraints allow you to put a condition on a template that must be true for the template to be able to be instantiated. For … Read more
To directly answer your two questions: Yes, creating class instances by reference does result in a lot of heap activity, but: a. In D, you have struct as well as class. A struct has value semantics and can do everything a class can, except polymorphism. b. Polymorphism and value semantics have never worked well together … Read more