typeinfo comparison - 'is' or '=='?

[Gregor Richards]

Partially to learn the DMD frontend and partially because it's cool and 
useful, I've been writing a D compiler targetting C ( 
http://www.dsource.org/projects/tdc/ )

I've ran into an issue with typeinfo objects.  It seems that for any 
type, there should be a static object containing the type info, and 
furthermore there should only be one in the output program.  My 
reasoning behind this is that several .d files in phobos/ use 'is' to 
compare typeinfo's, which implies to me that the 'typeid' operator will 
return a reference to a statically declared type (since otherwise it 
could return a different value and you'd get false negatives)

Unfortunately, this poses a bit of a problem when using .c as the 
output.  Anything I try to declare statically would end up declared into 
every .o file.  That's a (slightly) solvable problem with some linkers, 
but probably unsolvable with .so-linkage or .dll-linkage, unless I'm 
misunderstanding the situation.

So my question is: Am I wrong, or is the code in phobos/std/boxer.d and 
phobos/std/stream.d wrong?

  - Gregor Richards