On Tuesday, 7 September 2021 at 17:24:34 UTC, james.p.leblanc
wrote:
```d
/*…*/
// this is fine (notice that 'val' is never used
foreach( i, val ; u.tupleof ){
ptr = u.tupleof[i].x.ptr;
writeln("ptr: ", ptr);
}
// this fails with: "Error: variable 'i' cannot be read at
compile time
//
// foreach( i ; 0 .. 3 ){
// ptr = u.tupleof[i].x.ptr;
// writeln("ptr: ", ptr);
// }
}
```
As Adam mentioned `tupleof` only exists at compile time, and a
`foreach` over a `tupleof` gets unrolled at compile time, akin to
a `static foreach`. Consequently you can make your snippet work
by prepending `static` (and fixing the range):
```d
static foreach (i; 0 .. u.tupleof.length) {
ptr = u.tupleof[i].x.ptr;
writeln("ptr: ", ptr);
}
```
https://run.dlang.io/is/T6jrjf
Not sure if that helps in what you’re trying to achieve though,
as that isn’t clear to me.
—Bastiaan.
