Re: How can I check if a type is a pointer?
On Saturday, 25 June 2022 at 14:51:49 UTC, Paul Backus wrote:
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/xklcgjaqggihvhctc...@forum.dlang.org
Thank you too for this example! Have a nice day my friend!
Re: How can I check if a type is a pointer?
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/xklcgjaqggihvhctc...@forum.dlang.org
Re: How can I check if a type is a pointer?
On Saturday, 25 June 2022 at 14:32:27 UTC, Ola Fosheim Grøstad wrote: I guess you can look at the source code for https://dlang.org/phobos/std_traits.html#isPointer Thank you! Nice and quick ;) For anyone interested, here's the source code: ```d enum bool isPointer(T) = is(T == U*, U) && __traits(isScalar, T); ``` Have a nice day my friend!
Re: How can I check if a type is a pointer?
On Saturday, 25 June 2022 at 14:18:10 UTC, rempas wrote: In that example, the first comparison will execute the second branch and for the second comparison, it will execute the first branch. Of course, this trait doesn't exist I used an example to show what I want to do. Any ideas? I guess you can look at the source code for https://dlang.org/phobos/std_traits.html#isPointer
How can I check if a type is a pointer?
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
}
else { /* The type is not a pointer so its accepted */ }
if (__traits(isPointer, typeof(non_accepted_type))) {
// The type is not accepted
}
else { /* The type is not a pointer so its accepted */ }
}
```
In that example, the first comparison will execute the second
branch and for the second comparison,
it will execute the first branch. Of course, this trait doesn't
exist I used an example to show what I want
to do. Any ideas?
