c++ - Undefined reference to static class member -

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can explain why following code won't compile? @ least on g++ 4.2.4.

and more interesting, why compile when cast member int?

#include <vector>  class foo {   public:       static const int member = 1;   };  int main(){       vector<int> v;       v.push_back( foo::member );       // undefined reference `foo::member'     v.push_back( (int) foo::member ); // ok       return 0; }

you need define static member somewhere (after class definition). try this:

class foo { /* ... */ };  const int foo::member;  int main() { /* ... */ }

that should rid of undefined reference.


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