Do classes require explicit constructors?

[Brother Bill via Digitalmars-d-learn]

In Programming in D book, page 324, I've expanded this code as 
follows:

source/app.d
```
void main()
{
        auto variable1 = new MyClass(1);
        auto variable2 = new MyClass(2);
	// variable2 disassociates from new MyClass(2), where GC 
(garbage collector) can reclaim its memory
	// now both variable1 and variable2 are both referencing new 
MyClass(2)
        variable1 = variable2;

        assert(variable1 is variable2);
}

class MyClass
{
        int id;

        // this(int id)
        // {
        //      this.id = id;
        // }
}

```

This fails to compile with message:
```
c:\temp\c54_p324_1d_assignment\source\app.d(5): Error: no 
constructor for `MyClass`
    auto variable1 = new MyClass(1);
                     ^
c:\temp\c54_p324_1d_assignment\source\app.d(6): Error: no 
constructor for `MyClass`
    auto variable2 = new MyClass(2);
```

Is this expected behavior, that is, we always need to create our 
constructors, no free constructor is built for us by the D 
compiler?

If so, this is a clear departure from C# and Eiffel, where one 
gets a free constructor if no explicitly declared constructors.