First life-signs of type functions

[Stefan Koch]

On Tuesday, 19 May 2020 at 14:48:31 UTC, Stefan Koch wrote:
> On Tuesday, 19 May 2020 at 14:42:25 UTC, Stefan Koch wrote:
>> The branch is here (and should be green most of the time):
> Doh ... I have to actually link it :)
> And I didn't mean branch I meant PR ;)
> https://github.com/dlang/dmd/pull/11146

This test now works with the GREEN branch
auto getUDAs(alias T)
{
     return __traits(getAttributes, T);
     pragma(msg, typeof(return));
}

// we can't parse alias[];
alias alias_array = typeof(getUDAs(SerializeTag));

struct SerializeTag {}
struct SuperTag {string s;}

struct TypeWithTags
{
     alias type;
     alias_array tags;
}


TypeWithTags typeWithTags(alias T)
{
     auto udas = __traits(getAttributes, T);
     return TypeWithTags(T, udas);
}

@SuperTag("Smoking Super Style") @SerializeTag @SuperTag("Super!")
struct  ThisIsAType  { double y; }

alias x = ThisIsAType;

pragma(msg, "typeWithTags: ", typeWithTags(x));
//output: TypeWithTags((ThisIsAType), [SuperTag("Smoking Super 
Style"), (SerializeTag), SuperTag("Super!")])