void test(T)(T* arg);
void test(T)(ref T arg);

Let p be any pointer. Why is test(p) not an ambiguity error? Why is the second overload chosen?
Making the first one take auto ref T* lets the compiler choose the first.
Making the second one non-ref lets the compiler give me an ambiguity error.

Template Functions are not mentioned in the spec, at least not on https://dlang.org/spec/function.html#function-overloading, but it suggests that ref should not make the decision if it can be bound to.

Q. Schroll wrote:

> void test(T)(T* arg);
> void test(T)(ref T arg);
>
> Let p be any pointer. Why is test(p) not an ambiguity error? Why is the second overload chosen?

'cause `ref T` is more generic than `T*`. think of it as "greedy matching": compiler first tries to match `int*`, and if that failed, it tries `int`, for example. and `int*` matches the second template, so compiler choosing it.

On Wednesday, 15 March 2017 at 02:33:36 UTC, ketmar wrote:
> Q. Schroll wrote:
>
>> void test(T)(T* arg);
>> void test(T)(ref T arg);
>>
>> Let p be any pointer. Why is test(p) not an ambiguity error? Why is the second overload chosen?
>
> 'cause `ref T` is more generic than `T*`. think of it as "greedy matching": compiler first tries to match `int*`, and if that failed, it tries `int`, for example. and `int*` matches the second template, so compiler choosing it.

Wouldn't it be better vice versa, the more specific pattern to be prioritized? And as it actually *can* match both, is it a compiler-bug not to be an ambiguity error?