C:DEVELbuild-QtCurvesCPP-Desktop_Qt_5_11_1_MSVC2017_64bit-Debugui_mainwindow.h:35: error: C2061: syntax error: identifier 'renderArea'

#include <QWidget>

class renderArea : public QWidget
{
    Q_OBJECT
public:
    explicit renderArea(QWidget *parent = nullptr);

signals:

public slots:
};