What does it mean by "indirectly declaring a namespace within another namespace"?

Question

[basic.link] paragraph 4 in the C++14 Standard:

An unnamed namespace or a namespace declared directly or indirectly within an unnamed namespace has internal linkage. All other namespaces have external linkage. A name having namespace scope that has not been given internal linkage above has the same linkage as the enclosing namespace if it is the name of ...

What does it mean by "indirectly declaring a namespace within another namespace" above?

Possible duplicate of [Linkage of symbols within anonymous namespace within a regular namespace](http://stackoverflow.com/questions/4181059/linkage-of-symbols-within-anonymous-namespace-within-a-regular-namespace) — Alex, Oct 27 '15 at 20:34
@Alex I cannot see how the answers to that question answer this one. — Walter, Oct 27 '15 at 22:39

score 4 · Accepted Answer · answered Oct 27 '15 at 20:34

4

It means a namespace nested inside an unnamed namespace, so either a namespace declared as a member of an unnamed namespace, or declared as a member of a namespace declared as a member of an unnamed namespace, or so on.

answered Oct 27 '15 at 20:34

Brian Bi

111,498
10
176
312

But what's the difference between "directly" and "indirectly"? – Neil Kirk Oct 27 '15 at 20:36
4

@NeilKirk AFAIK "indirectly" just means not a direct member, but a member of a member, or so on. But I'm ready to be proven wrong. – Brian Bi Oct 27 '15 at 20:37
I'm trying to understand the difference between a namespace declared, direcltly versus indirectly, within another namespace. – Alexander Oct 27 '15 at 20:38
@Alexander Did you see my comment to NeilKirk? – Brian Bi Oct 27 '15 at 20:39
1

Yes, I did, but I'm still not convinced about your answer. – Alexander Oct 27 '15 at 20:46

What does it mean by "indirectly declaring a namespace within another namespace"?

1 Answers1