static immutable and lambdas inside struct or class. Is that bug or not?

[Uranuz via Digitalmars-d-learn]

On Sunday, 14 August 2016 at 15:53:21 UTC, ag0aep6g wrote:
> On 08/14/2016 04:27 PM, Uranuz wrote:
>> [...]
>
> Looks like a compiler bug, since it works without the struct:
>
> ----
> import std.algorithm: map;
> import std.array: array;
> import std.typecons: tuple;
>
>
> immutable aaa = [
> 	tuple("1", "one"),
> 	tuple("2", "two"),
> 	tuple("3", "three")
> ];
>
> immutable bbb = aaa.map!( a => a[0] ).array;
> ----
>
> And that's essentially the same thing.
>
> It has already been filed:
> https://issues.dlang.org/show_bug.cgi?id=15908
>
> For a workaround, it works when you explicitly state the type 
> of the parameter:
>
> ----
> struct A
> {
>     import std.algorithm: map;
>     import std.array: array;
>     import std.typecons: tuple, Tuple;
>
>
>     static immutable aaa = [
>         tuple("1", "one"),
>         tuple("2", "two"),
>         tuple("3", "three")
>     ];
>
>     alias Tup = Tuple!(string, string);
>     static immutable bbb = aaa.map!( (Tup a) => a[0] ).array;
> }
> ----

OK. I just declared alias for predicate outside struct to 
workaround. Maybe compiler trying to get context when attemting 
to infer arguments for some reason, but fails. Or something 
else...