I need to rewrite this post.

This is an example of how Qt builds class constructor which includes "form"
( I am not so sure naming class and form same name....).

Widget::Widget(QWidget *parent)
: QWidget(parent)
, ui(new Ui::Widget)
{
ui->setupUi(this);
}

This is how the actual class definition looks

QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
Q_OBJECT

public:
Widget(QWidget *parent = nullptr);
~Widget();

private:
Ui::Widget *ui;
};
#endif // WIDGET_H

Here is how my "form-less" class definition partially looks :

class CCC_MdiChild : public QTextEdit
{
Q_OBJECT

public:
CCC_MdiChild();

etc etc

and its constructor

CCC_MdiChild::CCC_MdiChild()
{
setAttribute(Qt::WA_DeleteOnClose);
isUntitled = true;
}

I have no issues adding "form.h" to the project....using QDesigner and QCreator

I need help adding "form.h" to the actual C++ code - class definition and to the default constructor.

Plain C++ - anybody ?

I'll keep this original post for a spell...

I have decided to add "form" to the project
I got as far as this and I have no idea what class is missing in the code

I got stomped by adding " ui_form" header, and recall discussing that long time ago. I guess this time it is "just the way it is "