g++ error messages

tool/includes/generator.h:23:45: error: ‘Generator<FUNC>::NAME’ has a previous declaration as ‘constexpr const char* const Generator<FUNC>::NAME’
tool/src/generator.cpp:14:37: error: declaration of ‘constexpr const char* const Generator<FUNC>::NAME’ outside of class is not definition [-fpermissive]

The original source code was (first header file, second implementation file):

template<class FUNC>
class Generator {
public:
  static constexpr const char* NAME = FUNC::NAME;
}

template<class FUNC>
constexpr char* SatGenerator<FUNC>::NAME;

<sarcasm>yeah, g++ is right.</sarcasm> I even claimed const twice as mentioned by the error message: const char* const. Occurs in g++ (Ubuntu/Linaro 4.7.2-2ubuntu1) 4.7.2 with C++11 standard.

g++ error messages