CWG Issue 2063 (original) (raw)

This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 118e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2025-11-05

2063. Type/nontype hiding in class scope

Section: _N4868_.6.4.1 [basic.scope.declarative]Status: CD4Submitter: Hubert TongDate: 2014-12-20

[Adopted at the February, 2016 meeting.]

The type/nontype hiding rules (“struct stathack”) do not apply in class scope. This is a C compatibility issue:

struct A { struct B { int x; } b; int B; // Permitted in C };

Since the type/nontype hiding rules exist for C compatibility, should this example be supported?

Proposed resolution (September, 2015):

Change _N4868_.6.4.1 [basic.scope.declarative] paragraph 4 as follows:

Given a set of declarations in a single declarative region, each of which specifies the same unqualified name,

• they shall all refer to the same entity, or all refer to functions and function templates; or
• exactly one declaration shall declare a class name or enumeration name that is not a typedef name and the other declarations shall all refer to the same variable, non-static data member, or enumerator, or all refer to functions and function templates; in this case the class name or enumeration name is hidden (_N4868_.6.4.10 [basic.scope.hiding]). [_Note:_ A namespace name or a class template name must be unique in its declarative region (9.9.3 [namespace.alias], Clause 13 [temp]). —_end note_]