On Friday, 26 September 2014 at 19:47:15 UTC, Steven
Schveighoffer wrote:
I wanted to bring this over from D.learn, because I've never
seen this before, and it's an interesting solution to creating
a property without much boilerplate.
So here it is:
class Foo
{
union
{
private int _a; // accessible only in this module
public const int a; // accessible from anywhere, but read
only
}
}
And it works now, probably has for a while.
Thoughts? This can easily be boilerplated in something like
roprop!(int, "a")
I am really not sure what union does to compiler optimization
or runtime concerns, if it has any significant drawbacks. From
what I can tell, it's a valid solution.
Credit to Mark Schütz for the idea.
-Steve
This is a clever syntax, but I can't say I particularly care for
it since it aliases two names for the same location which differ
only in their visibility, and this feels... wrong to me somehow.
In C# this is a sufficiently common practice that the property
syntax allows for it directly:
class Foo
{
int A { get; private set; }
}
The compiler automatically creates a (hidden) backing property
(this is an implementation detail of course), both internal and
external customers use the same name, and there is no redundancy.
If I were to compare the D way and the C# way, I would prefer to
C# way for this trivial-property case. What I would NOT want is
C#'s special handling of properties to go along with it - a D
analog would preserve A's access methods and handling as if it
were a field if that was the user's wish.
That's my $0.02.
