[LLVMbugs] [Bug 16668] New: Rejects-valid with variadic alias template in variadic class template

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=16668

            Bug ID: 16668
           Summary: Rejects-valid with variadic alias template in variadic
                    class template
           Product: clang
           Version: unspecified
          Hardware: PC
                OS: All
            Status: NEW
          Severity: normal
          Priority: P
         Component: C++11
          Assignee: unassignedclangbugs at nondot.org
          Reporter: sharparrow1 at yahoo.com
                CC: dgregor at apple.com, llvmbugs at cs.uiuc.edu,
                    richard-llvm at metafoo.co.uk
    Classification: Unclassified

Testcase:

template<int ...Args1> struct A {
    template<int ...Args2> using B = A<(Args1+Args2)...>;
};
template<int ...Args> using X = A<1,2,3>::B<Args...>;


Currently prints:
<stdin>:2:53: error: pack expansion contains parameter pack 'Args2' that has a
different length (3 vs. 1) from outer parameter packs
    template<int ...Args2> using B = A<(Args1+Args2)...>;
                                              ~~~~~ ^
<stdin>:4:43: note: in instantiation of template type alias 'B' requested here
template<int ...Args> using X = A<1,2,3>::B<Args...>;
                                          ^
1 error generated.

I don't see any obvious reason why this wouldn't be allowed by the standard.

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20130720/0823ce5d/attachment.html>