D and Go will probably just become as popular as Python and Ruby are today. They each fill a niche, and even though D was supposed to be a full-fledged replacement of C++, it probably will never acquire enough mass to push C++ away. Not to mention that they both aren’t stable/mature enough, and it’s … Read more
I believe that there are several places in D (such as returning structs) that D manages to make them moves whereas C++ would make them a copy. IIRC, the compiler will do a move rather than a copy in any case where it can determine that a copy isn’t needed, so struct copying is going … Read more
Reason #1 to choose struct vs class: classes have inheritance, structs do not. If you need polymorphism, you must use classes. Reason #2: structs are normally value types (though you can make them reference types if you work at it). Classes are always reference types. So, if you want a value type, choose a struct. … Read more
Personally, the most hideous problem I have seen is the invocation of template functions in dependent context: template <typename T> void foo(T t) { t.bar<3>(); } This looks admittedly simple, but in fact is incorrect. The C++ Standard requires the introduction of the template keyword to disambiguate t.bar < 3 vs a method invocation yielding: … Read more
It depends. There is no universal answer that is always going to be true. In Java, the JIT compiler will probably inline it sooner or later. As far as I know, the JVM JIT compiler only optimizes heavily used code, so you could see the function call overhead initially, until the getter/setter has been called … Read more
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