Manuel --
I read it and still don't get it. We know we should not warn about system headers but we do and that is a known bug. So again, why is libstdc++ using Wconversion at all?
I appreciate your help with this issue, and I'm confident that we'll soon converge to a nice solution. Thanks, really.
That said, frankly, I'm finding your saying, multiple times, "why is libstdc++ using Wconversion at all" particularly misleading, distracting and, well, annoying: libstdc++ is not using anything, by itself, certainly is not using Wconversion at .so and .a build time. The problem is that **the user of the library** may certainly compile **his own** code including libstdc++ headers passing a -Wconversion switch, or any other obscure request for warning. Then, given the bugginess of the pragma, which you correctly reminded (I just filed C++/30500 for that), warnings will be spilled from the libstdc++ headers to his face. He will be totally confused.
Let's agree about that simple point and move ahead. Thanks, Paolo.