[Bug c++/51604] New: [C++11][constexpr] Initializing static constexpr data members for class templates

["zsol.zs.ol+gcc at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51604

             Bug #: 51604
           Summary: [C++11][constexpr] Initializing static constexpr data
                    members for class templates
    Classification: Unclassified
           Product: gcc
           Version: 4.6.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsol.zs.ol+gcc@gmail.com


Created attachment 26125
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26125
Example preprocessed source which exhibits above behavior

This code, when compiled with g++ -std=c++0x -c test.cpp
on: g++ (Ubuntu/Linaro 4.6.1-9ubuntu3) 4.6.1

template <typename T>
class X {
static constexpr unsigned char hello[];
};

template <typename T>
constexpr unsigned char X<T>::hello[] = {0, 1};

Gives the following error:
/home/zsol/test.cpp:3:38: error: constexpr static data member âhelloâ must have
an initializer
/home/zsol/test.cpp:7:37: error: redeclaration âX<T>::helloâ differs in
âconstexprâ
/home/zsol/test.cpp:3:38: error: from previous declaration âX<T>::helloâ
/home/zsol/test.cpp:7:37: error: âX<T>::helloâ declared âconstexprâ outside its
class
/home/zsol/test.cpp:7:37: error: declaration of âconst unsigned char
X<T>::hello []â outside of class is not definition [-fpermissive]


GCC 4.5 (g++-4.5 (Ubuntu/Linaro 4.5.3-9ubuntu1) 4.5.4) compiles this happily.