6 Basics [basic]

6.4 Scope [basic.scope]

6.4.8 Template parameter scope [basic.scope.temp]

Each template template-parameter introduces a template parameter scope that includes the template-head of the template-parameter.
Each template-declaration D introduces a template parameter scope that extends from the beginning of its template-parameter-list to the end of the template-declaration.
Any declaration outside the template-parameter-list that would inhabit that scope instead inhabits the same scope as D.
The parent scope of any scope S that is not a template parameter scope is the smallest scope that contains S and is not a template parameter scope.
[Note 1:
Therefore, only template parameters belong to a template parameter scope, and only template parameter scopes have a template parameter scope as a parent scope.
— end note]