test22.cpp: In member function 'int Object1::func2(Data1*)':
test22.cpp:25:28: warning: Using parameter 'ptr1' without checking for null pointer
         Data1* ptr2 = ptr1 + 1;
                            ^
test22.cpp: In member function 'int Object1::func3(Data1*)':
test22.cpp:30:17: warning: Using parameter 'ptr1' without checking for null pointer
         Data1** ptr2 = &ptr1;
                 ^
test22.cpp: In member function 'void Object1::func4(Data1*)':
test22.cpp:36:24: warning: Using parameter 'ptr1' without checking for null pointer
         if (ptr1->ftest() == 100)
                        ^