How can I check if a type is a pointer?

[Paul Backus]

On Saturday, 25 June 2022 at 14:18:10 UTC, rempas wrote:
> For example, something like the following:
>
> ```d
> void main() {
>   char accepted_type;
>   char* non_accepted_type;
>
>   if (__traits(isPointer, typeof(accepted_type))) {
>     // The type is not accepted
>   }
> ```

Use an [`is()` expression:][1]

```d
if (is(typeof(accepted_type) == T*, T))
{
     // it's a pointer
}
```

In English, you read this as "if `typeof(accepted_type)` matches 
the pattern `T*`, where `T` is a type."

If you want to learn more, I recommend reading [Adam Ruppe's 
explanation of `is()` expressions][2].

[1]: https://dlang.org/spec/expression.html#IsExpression
[2]: 
https://forum.dlang.org/post/xklcgjaqggihvhctczxx@forum.dlang.org