libstdc++/3666: Invalid concept-checking code.

[mark@codesourcery.com]

>Number:         3666
>Category:       libstdc++
>Synopsis:       Invalid concept-checking code.
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jul 12 15:36:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     mark@codesourcery.com
>Release:        3.0
>Organization:
>Environment:

>Description:
The __glibcpp_class_requires macro sometimes expand
to the empty string, with the result that member
declarations consist of a single `;'.  That's not legal;
every member declaration must declare something.

An example class using this pattern is `vector' in 
stl_vector.h.
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: