Question

I’m trying to define the constructor that compiler generates automatically and resulted in an compilation error. Here is my code:

class myclass
 {
   public:
       void Test_Func()
       {}
 };
myclass::myclass()
{
}

Is compiler doing anything in addition for a simple class like above. Here is the error that I got in MSVC compiler:

"error C2600: 'myclass::myclass' : cannot define a compiler-generated special member function (must be declared in the class first)"

Answer 1

The synthesised constructor is both declared and defined. You may not define it yourself.

You’ll have to declare your own constructor in order to provide an implementation.

[special] (2003 wording, 12/1) says:

The default constructor (12.1), copy
constructor and copy assignment
operator (12.8), and destructor (12.4)
are special member functions. The
implementation will implicitly declare
these member functions for a class
type when the program does not
explicitly declare them, except as
noted in 12.1. The implementation will
implicitly define them if they are
used, as specified in 12.1, 12.4 and
12.8. Programs shall not define implicitly-declared special member
functions.