Suppose we are often writing something like

theFirstName[theFirstIndex].theSecondName[theSecondIndex].thirdName[theThirdIndex]=x;

One would like to something like

alias shortName = theFirstName[theFirstIndex].theSecondName[theSecondIndex].thirdName[theThirdIndex];
shortName = x;

but you can't alias an expression.

You can do

(ref shortName) {
 shortName = x;

}(theFirstName[theFirstIndex].theSecondName[theSecondIndex].thirdName[theThirdIndex]);

but that doesn't read well since the ``definition'' of shortName comes at the end.

Another option is

auto aliasAs(alias f,T)(ref T x) { return f(x); }

theFirstName[theFirstIndex].theSecondName[theSecondIndex].thirdName[theThirdIndex].aliasAs!
(ref shorName) {
 shortName = x;
}

Thoughts?

On 6/21/22 1:09 PM, JG wrote:

Use a pointer? Especially if you are using .method calls, this just works seamlessly.

-Steve

On Tuesday, 21 June 2022 at 17:15:02 UTC, Steven Schveighoffer wrote:

Thanks for the suggestion. My immediate reaction is that for .method calls I would agree, but for assignments it is slightly less pleasant. Perhaps it is the best option.

On 6/21/22 1:19 PM, JG wrote:

I use pointers for this purpose all the time. It's what they are for (to point at something).

They even work in safe functions with dip1000 turned on.

Yes it can get tedious to have to dereference in many cases. But at least if you forget and assign to t instead of *t, it probably doesn't compile.

-Steve

On Tuesday, 21 June 2022 at 17:09:28 UTC, JG wrote:

theFirstName[theFirstIndex].theSecondName[theSecondIndex].thirdName[theThirdIndex]=x;

alias shortName = theFirstName[theFirstIndex].theSecondName[theSecondIndex].thirdName[theThirdIndex];
shortName = x;

Maybe check out std.meta.Alias?

https://dlang.org/phobos/std_meta.html#.Alias