On Saturday, 6 November 2021 at 04:28:05 UTC, Ali Çehreli wrote:
On 11/5/21 5:43 PM, Andrey Zherikov wrote:
In case others want to work, here are the modules that need to
be imported:
import std.algorithm;
import std.range;
import std.stdio;
> struct A {}
> struct B
> {
> A[] ar = [A.init];
> size_t[] idx = [0];
I don't know why but those initial values are the reason for
the problem. It works without them.
`get()` will return nothing in this case. But I can make them non
empty in another way:
```d
import std;
struct A {}
struct B
{
A[] ar;
size_t[] idx;
A*[] get()
{
return idx.map!((idx) => &ar[idx]).array;
}
}
auto foo()
{
B b;
b.ar ~= A.init;
b.idx ~= 0;
return b.get();
}
void main()
{
writeln(foo());
pragma(msg, foo());
}
```
Some one can complain that `foo()` returns pointers that are not
available in CTFE but remember that the real code is more complex
and `foo()` cam be return just length (`return b.get().length;`)
having the same result.
Basically I have a collection of data (`A[] ar`), different
addressing through the indexes (multiple `size_t[] idx`) and I
want to manipulate these objects through indexes. If there is
another way to achieve the same in CFTE, I'd like to hear.
