Namespace association: ODR violation made easy

[Paolo Carlini]

Gabriel Dos Reis wrote:

>A recent PR about "user forward declaring" entities in namespace std
>reminded me about a message I sent to Benjamin, Matt and Jason more
>than two months ago.  Since 3.4.0 is imminent, I think something
>should go in our docs; I don't what, but I believe people may soon
>start reporting PRs about.
>
I completely agree with you, given, in particular, that the PR you are
hinting to (14370), was distilled from "Boost" and that the EDG front
end accepts it in strict mode.... Ergo the issue seems not completely
trivial ;)

Paolo.