ParameterIdentifierTuple produces different results depending on whether unnamed parameters are built-in types or user types.

struct SomeType {
  void wrong(SomeType) {}
  void right(int) {}
}

ParameterIdentifierTuple!(__traits(getMember, SomeType, "wrong")); // tuple("SomeType")
ParameterIdentifierTuple!(__traits(getMember, SomeType, "right")); // tuple("")

Is this the intended behaviour? Shouldn't it just return empty strings in both cases? What would be the benefit of returning user type names?

On Fri, 30 Nov 2018 18:18:36 +0000, John Chapman wrote:
> ParameterIdentifierTuple!(__traits(getMember, SomeType, "wrong"));
> // tuple("SomeType")
> ParameterIdentifierTuple!(__traits(getMember, SomeType, "right"));
> // tuple("")

Compiler and version would be helpful here.

I'm on DMD 2.081.1 and it yields the same results in each case: _param_0

On Friday, 30 November 2018 at 19:07:14 UTC, Neia Neutuladh wrote:
> Compiler and version would be helpful here.
>
> I'm on DMD 2.081.1 and it yields the same results in each case: _param_0

Hmm, I was calling ParameterIdentifierTuple inside a lambda - once I moved it into my main function I got the same output as you.

But … change SomeType to an interface and it reproduces the issue I reported above.

interface SomeType {
  void wrong(SomeType);
  void right(int);
}

I'm on DMD 2.083.0.

On Friday, 30 November 2018 at 19:37:52 UTC, John Chapman wrote:
> On Friday, 30 November 2018 at 19:07:14 UTC, Neia Neutuladh wrote:
>> Compiler and version would be helpful here.
>>
>> I'm on DMD 2.081.1 and it yields the same results in each case: _param_0
>
> Hmm, I was calling ParameterIdentifierTuple inside a lambda - once I moved it into my main function I got the same output as you.
>
> But … change SomeType to an interface and it reproduces the issue I reported above.
>
> interface SomeType {
>   void wrong(SomeType);
>   void right(int);
> }
>
> I'm on DMD 2.083.0.

On Friday, 30 November 2018 at 19:37:52 UTC, John Chapman wrote:

This is pretty broken so I've opened a bug: https://issues.dlang.org/show_bug.cgi?id=19456