corrected compiler incompatibility

brainywindow.cpp

@@ -14,8 +14,8 @@ BrainyWindow::BrainyWindow(QWidget *parent) :
     ui->setupUi(this);
     sh = new SyntaxHighlighter(ui->textEdit->document());
 
-    ui->actionOpen_2->connect(ui->actionOpen_2, &QAction::triggered, this, openFile);
-    ui->actionSave_2->connect(ui->actionSave_2, &QAction::triggered, this, saveFile);
+    ui->actionOpen_2->connect(ui->actionOpen_2, &QAction::triggered, this, &BrainyWindow::openFile);
+    ui->actionSave_2->connect(ui->actionSave_2, &QAction::triggered, this, &BrainyWindow::saveFile);
     ui->actionEditor_Font->connect(ui->actionEditor_Font, &QAction::triggered, this, [this] () {
         bool ok;
         QFont font = QFontDialog::getFont(&ok, ui->textEdit->font(), this);