c++ - Qualified access needed when inheriting from template -

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• accessing inherited variable templated parent class 2 answers

in situation this, why can't access base class member x unqualified in b1 case? doesn't loook ambiguous me…

template<class t> struct { t x; };  template<class t> struct b1 : a<t> { t f() { return a<t>::x; } };  struct b2 : a<int> { int f() { return x; } }; 

because x not dependent, looked in context template defined. in context, compiler knows nothing of t, , cannot in dependent base classes. how can it, example, know of a<t> without knowing t is. (there specialization of a example, different members.)