Re: How to correctly generate enums at compile time.

[jkpl via Digitalmars-d-learn]

On Sunday, 30 April 2017 at 20:05:59 UTC, Kevin Balbas wrote:
I've got the following code snippet, which almost does what I 
want.

struct TaggedType {}

@TaggedType
struct Foo {}

@TaggedType
struct Bar {}

string GenerateTypeEnum()
{
    string enumString = "enum TypeEnum {";
    foreach (name; __traits(allMembers, mixin(__MODULE__)))
    {
        import std.traits;
        static if (hasUDA!(mixin(name), TaggedType))
        {
            enumString ~= name;
            enumString ~= "Type,";
        }
    }
    enumString ~= "}";
    return enumString;
}

// generates enum TypeEnum {FooType,BarType,}
mixin(GenerateTypeEnum());

This works great, except that TypeEnum isn't accessible from 
other modules (undefined identifier 'TypeEnum'), which is kind 
of the point of doing this (I'm using the enum as a system-wide 
tag for inter-thread communication).  I can imagine why this 
would be the case, but it's a pretty serious problem.  Is there 
a way to do this?

if i put your sniped in b.d and import in a.d b then i'm able to 
access TypeEnum.
You r problem must be something stupid that's not related to 
UDA/mixins.

That leads to this question (sorry) but at least do you import 
the module that contains TypeEnum ?