Type info is always generated for struct that contain structs that have an alias this. This was apparently done because of https://issues.dlang.org/show_bug.cgi?id=14948 and "fixed" in https://github.com/dlang/dmd/pull/5001 , see also https://github.com/dlang/dmd/blob/master/src/ddmd/clone.d#L655 with the comment bugzilla link.

I have a couple of issues with this approach:
1) it builds typeinfo even if it is not used (the above issue involves using such a struct in an AA where it _is_ used, which is fine).
2) it does not respect -betterC, so there is no way to not have typeinfo which, IMO, makes -betterC rather useless.

Can we be more discerning with generation of typeinfo? i.e. generate it lazily and only if used, perhaps with weak linkage so end users can have it if they need it?

On 09.07.2017 05:31, Nicholas Wilson wrote:
> Type info is always generated for struct that contain structs that have an alias this. This was apparently done because of https://issues.dlang.org/show_bug.cgi?id=14948 and "fixed" in https://github.com/dlang/dmd/pull/5001 , see also https://github.com/dlang/dmd/blob/master/src/ddmd/clone.d#L655 with the comment bugzilla link.
> 
> I have a couple of issues with this approach:
> 1) it builds typeinfo even if it is not used (the above issue involves using such a struct in an AA where it _is_ used, which is fine).
> 2) it does not respect -betterC, so there is no way to not have typeinfo which, IMO, makes -betterC rather useless.
> 
> Can we be more discerning with generation of typeinfo? i.e. generate it lazily and only if used, perhaps with weak linkage so end users can have it if they need it?

There is a pull request by Walter to generate the type info on demand: https://github.com/dlang/dmd/pull/6561

Unfortunately it seems to need a bit more work.