[Endilll]

[basic.lookup.unqual]/2 reads:

An unqualified search in a scope S from a program point P includes the results of searches from P in
— (2.1) S, and
— (2.2) for any scope U that contains P and is or is contained by S, each namespace contained by S that is nominated by a using-directive that is active in U at P.
If no declarations are found, the results of the unqualified search are the results of an unqualified search in the parent scope of S, if any, from P.

It always takes me a while to understand 2.2 every time I see it, because it's denser than the surrounding text, and also the mechanics it describes is not the most intuitive. This PR adds an example for 2.2 and the sentence that follows for the benefit of the readers. All four implementations agree: https://godbolt.org/z/KE3oM3eET