use placement new for creating dos objects about fdpp HOT 2 CLOSED

/home/stas/src/fdpp/fdpp/farptr.hpp:97:38: error: call to implicitly-deleted
      default constructor of 'FarPtrBase<const char>::wrp_type' (aka
      'SymWrp2<const char>')
        wrp_type *s = new(get_buf()) wrp_type;
                                     ^
/home/stas/src/fdpp/fdpp/farptr.hpp:102:43: note: in instantiation of member
      function 'FarPtrBase<const char>::get_wrp' requested here
        return FarPtrBase<T>(*this + idx).get_wrp();
                                          ^
dosfns.cc:1288:46: note: in instantiation of member function 'FarPtrBase<const
      char>::operator[]' requested here
      unsigned char c1 = (unsigned char)froot[i];
                                             ^
/home/stas/src/fdpp/fdpp/farptr.hpp:279:5: note: explicitly defaulted function
      was implicitly deleted here
    SymWrp2() = default;
    ^
/home/stas/src/fdpp/fdpp/farptr.hpp:276:7: note: default constructor of
      'SymWrp2<const char>' is implicitly deleted because field 'sym' of
      const-qualified type 'const char' would not be initialized
    T sym;
      ^
1 error generated.