Comment by WalterBright
15 hours ago
D is an elegant re-imagine of C and C++. For a trivial example,
typedef struct S { int a; } S;
becomes simply:
struct S { int a; }
and unlike C:
extern int foo();
int bar() { return foo(); }
int foo() { return 6; }
you have:
int bar() { return foo(); }
int foo() { return 6; }
For more complex things:
#include <foo.h>
becomes:
import foo;
Your first example doesn't make sense, because
is also fine and idiomatic in C. It is rather
that doesn't make sense, because why would you make something opaque and expose it immediately again in the same line?
The others are ... different. I can't tell whether they are really better. The second maybe, although I like it that the compiler forces me to forward type stuff, it makes the code much more readable. But then again I don't really get the benefit of
vs
.
include vs import is no difference. # vs nothing makes it clear that it is a separate feature instead of just a language keyword. < vs " make it clear whether you use your own stuff or stuff from the system. What do you do when your file contains spaces? Does import foo bar; work for including a file a single file, named "foo bar"?
Smoe of these are definitely nice-to-haves*, but when you're evaluating a C++ alternative, there are higher priority features to research first.
How are the build times? What does its package system(s) look like, and how populated are they? What are all its memory management options? How does it do error handling and what does that look like in real world code? Does it have any memory safety features, and what are their devtime/comptime/runtime costs? Does it let me participate in compile time optimizations or computations?
Don't get me wrong, we're on the same page about wanting to find a language that fills the C++ niche, even if it will never be as ideal as C++ in some areas (since C++ is significantly worse in other areas, so it's a fair trade off). But just like dating, I'm imagining the fights I'll have with the compiler 3 months into a full time project, not the benefits I'll get in the first 3 days.
* (a) I've been using structs without typedef without issue lately, which has its own benefits such as clarifying whether the type is simple or aggregate in param lists, while auto removes the noise in function bodies. (b) Not needing forward declarations is convenient, but afaik it can't not increase compile times at least somewhat. (c) I like the consistency here, but that's merely a principle; I don't see any practical benefit.
Build times are quite a bit faster.
The package system is called dub.
Memory management options include:
1. stack allocation
2. malloc allocation
3. write your own allocator
4. static allocation
5. garbage collection
You can use exceptions or returns for error handling.
The biggest memory safety feature it has is length-delimited arrays. No more array overflows! The cost of it is the same as in std::vector when you do the bounds checked option. D also uses refs, relegating pointers to unusual uses. I don't know what you mean by "participating in optimizations".
(a) C doesn't have the hack that C++ has regarding the tag names. D has auto.
(b) D has much faster compile times than C++.
(c) The practical benefit is the language is much easier to master.
Everything except the import looks like standard c++ since at least 98.
C++ does not allow forward references outside of structs. The point-of-instantiation and point-of-declaration rules for templates produces all kinds of subtle problems. D does not have that issue.
Yes, you absolutely can get the job done with C and C++. But neither is an elegant language, and that puts a cognitive drag on writing and understanding code.