Strange, I thought I had left a message about this before, but I can't find it anymore. Maybe someone deleted it? There's no un-delete in git-hub, AFAIK?

Anyways, this mostly looks good to me, and I would have pulled this earlier, but I do have a reservation: It's the:
```D
Cpp = "C++",
```
What troubles me is that:
```D
void main()
{
    auto a = LinkageType.Cpp;
    assert(a == "C++");
    writeln(a);
}
```
Prints
```D
Cpp
```

In particular, I could see this potentially breaking code generating code, that does things such as
```
mixin(format("extern (%s) foo()", functionLinkage!foo));
```

Do you think this might be a problem?