Jens Maurer
N3259=11-0029
2011-03-22

Core Issue 355: Global-scope :: in elaborated-type-specifier

This paper presents the wording changes relative to the Working Paper N3242 to address core issue 355 (see also FCD comments US 2 and CH 1). Due to the volume of the changes, they were not integrated into the core issues list.

In section 3.4.3 basic.lookup.qual paragraph 6, change the grammar snippet as follows: 

::opt nested-name-specifieropt class-name :: ~ class-name



In section 3.4.3.2 namespace.qual, replace as indicated:


If the nested-name-specifier of a qualified-id
nominates a namespace, the name specified after the
nested-name-specifier is looked up in the scope of the
namespace,

.  If a qualified-id starts with
::, the name after the :: is looked up
in the global namespace.

In either case, except that the names in a
template-argument of
a template-id are looked up in the context in which the
entire postfix-expression occurs.



Strike 5.1.1 expr.prim.general paragraph 3 entirely:


The operator :: followed by an identifier,
a qualified-id, an operator-function-id, or a
literal-operator-id is a primary-expression. Its
type is specified by the declaration of the identifier,
qualified-id, operator-function-id, or
literal-operator-id. The result is the entity denoted by the
identifier, qualified-id,
operator-function-id, or literal-operator-id. The
result is an lvalue if the entity is a function or variable and a
prvalue otherwise.
The identifier, qualified-id,
operator-function-id, or literal-operator-id shall
have global namespace scope or be visible in global scope because of a
using-directive (7.3.4 namespace.udir). [ Note: the use of
:: allows an entity declared in the global namespace to
be referred to even if its name has been hidden (3.4.3
basic.lookup.qual). -- end note ]



Drafting note: It's covered by 5.1.1p7 (type, lvalue-ness,
member-ness, reference to 3.4.3.2) and 3.4.3.2 (qualified lookup for
namespace members).



In section 5.1.1 expr.prim.general paragraph 6, change the grammar
snippet as follows:



qualified-id:
       ::opt nested-name-specifier templateopt unqualified-id
       :: identifier
       :: operator-function-id
       :: literal-operator-id
       :: template-id

nested-name-specifier:
       ::opt type-name ::
       ::opt namespace-name ::
       decltype-specifier ::
       nested-name-specifier identifier ::
       nested-name-specifier templateopt simple-template-id ::






In section 5.1.1 expr.prim.general paragraph 7, replace as indicated:


A ::, or a
nested-name-specifier that names a namespace (7.3
basic.namespace),
in either case followed by the name of a member of
that namespace (or the name of a member of a namespace made visible by a
using-directive) is a qualified-id; 3.4.3.2 namespace.qual describes
name lookup for namespace members that appear in
qualified-ids. ...



In section 5.1.1 expr.prim.general paragraph 9, replace as indicated:


In a qualified-id, if the
id-expression unqualified-id
is a conversion-function-id,
its conversion-type-id shall denote the same type in both the
context in which the entire qualified-id occurs and in the
context of the class denoted by the nested-name-specifier.



In section 5.2 expr.post paragraph 1, change the grammar as indicated:



...
pseudo-destructor-name:
      ::opt nested-name-specifieropt type-name :: ~ type-name
      ::opt nested-name-specifier template simple-template-id :: ~ type-name
      ::opt nested-name-specifieropt ~ type-name
      ~ decltype-specifier





In section 5.2.4 expr.pseudo paragraph 2, change the grammar snippet
as indicated:



::optnested-name-specifieropt type-name :: ~ type-name





In 7.1.6.2 dcl.type.simple paragraph 1, change the grammar snippet
as indicated:



simple-type-specifier:
       ::opt nested-name-specifieropt type-name
       ::opt nested-name-specifier template simple-template-id
       char
       ...






In 7.1.6.3 dcl.type.elab before paragraph 1, change the grammar snippet
as indicated:



elaborated-type-specifier:
      class-key attribute-specifieropt ::opt nested-name-specifieropt identifier
      class-key ::opt nested-name-specifieropt templateopt simple-template-id
      enum ::opt nested-name-specifieropt identifier





In 7.1.6.3 dcl.type.elab paragraph 1, change the grammar snippet
as indicated:



class-key attribute-specifieropt identifier ;
friend class-key ::opt identifier ;
friend class-key ::opt simple-template-id ;
friend class-key ::opt nested-name-specifier identifier ;
friend class-key ::opt nested-name-specifier templateopt simple-template-id ;







In 7.3.2 namespace.alias paragraph 1, change the grammar snippet
as indicated:



qualified-namespace-specifier:
       ::opt nested-name-specifieropt namespace-name




In 7.3.3 namespace.udecl paragraph 1, change the grammar snippet
as indicated:



using-declaration:
       using typenameopt ::opt nested-name-specifier unqualified-id ;
       using :: unqualified-id ;




In section 7.3.4 namespace.udir before paragraph 1, change the grammar snippet
as indicated:




using-directive:
       attribute-specifieropt using namespace ::opt nested-name-specifieropt namespace-name ;




In clause 8 dcl.decl paragraph 4, change the grammar snippet
as indicated:



...
ptr-operator:
      * attribute-specifieropt cv-qualifier-seqopt
      & attribute-specifieropt
      && attribute-specifieropt
      ::opt nested-name-specifier * attribute-specifieropt cv-qualifier-seqopt
...
declarator-id:
      ...opt id-expression
      ::opt nested-name-specifieropt class-name





In section 8.3.3 dcl.mptr paragraph 1, change the grammar snippet
as indicated:




::opt nested-name-specifier * attribute-specifieropt cv-qualifier-seqopt D1




In section 9.2 class.mem before paragraph 1, change the grammar snippet
as indicated:




member-declaration:
     attribute-specifieropt decl-specifier-seqopt member-declarator-listopt ;
     function-definition ;opt
     ::opt nested-name-specifier templateopt unqualified-id ;
     using-declaration
     static_assert-declaration
     template-declaration
     alias-declaration





In clause 10 class.derived paragraph 1, change the grammar snippet
as indicated:



...
class-or-decltype:
       ::opt nested-name-specifieropt class-name
       decltype-specifier
...





In section 14.6 temp.res paragraph 3, change the grammar snippet
as indicated:



typename-specifier:
      typename ::opt nested-name-specifier identifier
      typename ::opt nested-name-specifier templateopt simple-template-id