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any idea why it is failing on the win with lld-link? t seems kinda arbitrary

This could be related/help: dlang/dmd#10525

@John-Colvin so the failure on win64 doesn't seem related to the other thing but have you confirmed this works on win32? or is that talk about the throw function and catch tables needing to be merged mean there's still a lot to do?

Using ClassInfo.name isn't good enough for the same reason as https://issues.dlang.org/show_bug.cgi?id=20579

class A(T) {}
template B(T) {
    struct C {}
}

void main() {
    assert(A!(B!int.C).classinfo.name != A!(B!string.C).classinfo.name); // assertion failure!
}

I think the only way to fix this properly is to put the mangle of a type into ClassInfo and compare that. If you're going to do that, I suggest using that to fix TypeInfo.opEquals while we're at it. I think we would just need the mangle in TypeInfo_Struct, TypeInfo_Class and TypeInfo_Enum + this change then both casting and TypeInfo.opEquals will work.

alas mangleof isn't available for subclasses... that means we need a dmd change to make the information available. and mangles can be absurdly large. idk.

Or some other unique name, but it must be unique that the problem. Something like std.traits.fullyQualifiedName looks like it does the trick. There's a reason they get long - they have to be unique.

You can mitigate the cost of doing this by versioning it out on non-Windows platforms and with a little effort you can work out if you're in a different DLL and only do the string comparison in those cases.

fullyQualfiedName i think also doesn't work without virtuals

but i did just remember we have RTInfo so it doesn't need a dmd change per se; it can be done at CT with rtinfo in object.d. not a bad idea, might work at least as a hack.

How does RTInfo help?

Ah that's the badger!

TypeInfo names of classes, structs and interfaces are unique now after #3527.

This has landed in #3543, thx John.

This has landed in #3543, thx John.

Thanks for sorting this out, sorry for abandoning it for so long