I thought if I don't use a particular member function of a class template it never gets constructed by the compiler. Hence as expected even with f1() compiles fine because obj never uses it. Why does f0() result in compile error? I'm not using that too.
The implicit instantiation of a class template specialization
Is this meant to deal with class template specialization? Because I haven't specialized DEF. (That's one of the reasons I generally can't fully comprehend the draft/standard - I get confused by the wordings and lack of thorough knowledge of the language)