As we saw over in the "[fusion] change on trunk breaking proto" thread, even VC10 has bugs that cause random failures in proto's tests. Using proto isn't necessarily a talisman against compile errors.

Sure. In this case, proto has only a very limited role, at most the one of a trigger. Specifically, VC8 has problems with enable_if for template class specializations. Interestingly, it has a problem with Process2_ eventhough it doesn't even use it, just including the header is enough to get the bug. Even more interesting, the next template specialization (Get_Flag_) doesn't seem to disturb the compiler... Anyway, all VC compilers suffer from the same disease. Most template constructs will manage to compile once, but repeat the operation too much and it gives up. I'd bet that Microsoft uses tons of test cases which try any construct once. I actually only try to support eUML for VC8 to honor the fact that it implemented a typeof back in 2005. Christophe