D on quora ...

[Ola Fosheim Grøstad]

On Saturday, 7 October 2017 at 15:12:08 UTC, Random D user wrote:
> Actually, Manual Memory Management is slow and D's GC is slower.

Well, no, deterministic memory management isn't slow. One 
specific implementation with a high level of naiveté might be 
slow.

C is not a very clever language, it was designed to be minimal 
and with minimal compiler requirements and with most features 
pushed onto libraries, including memory management. C++ is just 
meta-level dressing over C…

> Because, if malloc/free is slow (free is often slower), you 
> want to avoid them as much as possible.

A naive generic library implementation that is used randomly will 
not be fast, but a more dedicated implementation for the program 
at hand could be very performant.

> You do this by reusing your memory/buffers.

Yes, in C/C++ you either have to resort to creating your own 
allocator in your program or you could used dedicated allocators. 
Or you just make them static global.

Anyway, D doesn't improve on C/C++ when it comes to allocators. 
And it's garbage collector is pretty much stuck in the standard 
GC implementation from 1960s/1970s in terms of performance and 
features.

Just because C/C++ is primitive doesn't mean that D is doing 
well, but at this point there is not much hope of D becoming a 
significant improvement on C++… So maybe it is better for D to 
stay where it is as there is basically very little support among 
the designers from improving the language semantics. In the C++ 
environment there is at least some movement, so maybe it will 
become a decent language in 2050, although they are stuck with 
the primitive C-foundation…