It seems there is a contradiction in the C++ 20 Standard relative to the enclosing namespace.

According to the section 9.7.1 Namespace definition of the C++ 20 Standard a namespace definition is a declaration

3 Because a namespace-definition contains declarations in its namespace-body and a namespace-definition is itself a declaration, it follows that namespace-definitions can be nested.

Farther

4 The enclosing namespaces of a declaration are those namespaces in which the declaration lexically appears, except for a redeclaration of a namespace member outside its original namespace (e.g., a definition as specified in 9.7.1.2).

And now

8. ...The enclosing namespace set of O is the set of namespaces consisting of the innermost non-inline namespace enclosing an inline namespace O, together with any intervening inline namespaces.

A question arises whether an inline namespace is a declaration?:) Because its enclosing namespace is not the same as the enclosing namespace of a declaration.

I think that the last quote should have some additional clarification words.

With best regards
(Vlad from Moscow)

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