On Monday, 8 August 2022 at 05:38:31 UTC, rempas wrote:
In the following struct (as an example, not real code):
```
struct TestArray(ulong element_n) {
int[element_n] elements;
this(string type)(ulong number) {
pragma(msg, "The type is: " ~ typeof(type).stringof);
}
}
```
I want to create it and be able to successfully initialize the
template parameters
of the constructor but until now, I wasn't able to find a way
to successfully do
that. Is there a way you guys know? I have tried the following:
```
void main() {
// Doesn't work
auto val = TestArray!(10, "int")(60);
// Doesn't work either
auto val = TestArray!(10).TestArray!("int")(60);
// Neither this works....
auto val = TestArray!(10).this!("int")(60);
}
```
As with every question I make, the solution must be "betterC"
compatible so I can use it.
Thanks a lot!
I would move the constructor out of the struct into a helper
function, either global or as a static member:
```d
TestArray!n testArray(ulong n, string type)(ulong number) {
TestArray!n ret;
pragma(msg, "The type is: " ~ typeof(type).stringof);
ret.something = something; // do your constructor logic here
return ret;
}
```
which you can then use:
```d
auto t = testArray!(10, "int")(60);
```
As the template parameter being part of the constructor would
only change the constructor (and can't change anything like types
outside the ctor) it doesn't have any limitations and if you
define it in the same module as the struct you can also access
the private members.
