How to abuse a C++ compiler?(mysticalprogramming.wordpress.com)

    ~/test/O$ cat break.cpp 
    
    #include <iostream>
    
    template <typename A, typename B>
    struct MutualRecursion {
      static const int a = MutualRecursion< B, A >::b ;
      static const int b = MutualRecursion< B, A >::a ;
    };
    
    int main( int argc, char ** argv ){
      std::cout << MutualRecursion< float, int >::b << std::endl;
      return 0;
    };
    ~/test/O$ clang break.cpp 
    break.cpp:6:49: error: no member named 'b' in 'MutualRecursion<float, int>'
      static const int a = MutualRecursion< B, A >::b ;
                           ~~~~~~~~~~~~~~~~~~~~~~~~~^
    break.cpp:6:24: note: in instantiation of template class 'MutualRecursion<int, float>' requested here
      static const int a = MutualRecursion< B, A >::b ;
                           ^
    break.cpp:11:16: note: in instantiation of template class 'MutualRecursion<float, int>' requested here
      std::cout << MutualRecursion< float, int >::b << std::endl;
                   ^
    break.cpp:7:24: error: in-class initializer is not a constant expression
      static const int b = MutualRecursion< B, A >::a ;
                           ^~~~~~~~~~~~~~~~~~~~~~~~~~
    2 errors generated.
    ~/test/O$ 

      // static const int b = MutualRecursion< B, A >::a ;                                                                                                                                                                                                                                                                                         
      static const int b = 10 ;