[dcl.typedef] p2 Unexplained lookup "error" in example

[jensmaurer]

using cell = pair<void*, cell*>;    // error

Two issues: pair is undefined here (is it std::pair?) and the error is unexplained.
The explanation for the error is in [basic.scope.pdecl] p4:

The locus of a using-declarator that does not name a constructor is immediately after the using-declarator (9.9).

Source: Vladimir Grigoriev on std-discussion 2021-11-13

[xmh0511]

It seems there is nothing related to using-declarator since the declaration is not a using-declaration; it's just an alias-declaration. Presumably, the explanation is in [basic.scope.pdecl] p3

The locus of an alias-declaration is immediately after it.

So, the name cannot be found until the end of the alias-declaration.

[jensmaurer]

Oh, right, I was confused.