DIP45: fixing the dllimport/dllexport issue

[Martin Nowak]

>> I also kind of feel that we need to export lib1 as well, as you may not
>> know what lib2 does with what it gets from lib1 (passing objects around
>> for instance). So certainly at least some part of lib1 need to be
>> exported.
For sure lib2 might forward to some lib1 symbols.
Not sure what might accidentally require linkage.

> I don't agree if that statement. If you have three libs. lib1, lib2 and
> lib3. And lib2 and lib3 link statically against lib1 you are going to
> get linker errors because both lib2 and lib3 contain the symbols of lib1.

A: Why do two DLLs which export the same symbols cause linker errors? 
Because the corresponding import libraries contain the same symbols?
B: You shouldn't mix static with dynamic linking, ODR issues are what 
you get in return.
C: What would happen if you statically link against lib2 and lib3?