Several changes:

 - Adding some missing documentation to WButtonGroup, 0 -> nullptr

   It was not specified that WButtonGroup::button(int) returns null if the
   button is not found

   Wt 4 uses C++11, so let's refer to a null pointer as nullptr.

 - Eliminated dubious std::unique_ptr<...>(this) in ColumnWidget constructor

   clang-analyzer was warning about a possible memory leak after calls to
   new ColumnWidget(...).

   It shouldn't normally leak, since the newly created ColumnWidget* is
   actually put into a unique_ptr and then moved into either table_ or
   headerColumnsTable_, but std::unique_ptr<WWidget> self(this) is a rather
   dubious hack. We can do this in a nicer (safer, more guaranteed to be
   defined behaviour) way.

Author: RockinRoel

src/Wt/WButtonGroup.h

@@ -101,6 +101,8 @@ class WT_API WButtonGroup : public WObject
   void removeButton(WRadioButton *button);
 
   /*! \brief Returns the button for the given id.
+   *
+   * Returns \c nullptr if no button exists for the given id.
    *
    * \sa id(), addButton()
    */
@@ -143,7 +145,7 @@ class WT_API WButtonGroup : public WObject
   /*! \brief Returns the checked radiobutton.
    *
    * If there is no radiobutton currently checked this function
-   * returns \c 0.
+   * returns \c nullptr.
    *
    * \sa setCheckedButton(), selectedButtonIndex()
    */

src/Wt/WTableView.C

@@ -490,7 +490,7 @@ void WTableView::addSection(const Side side)
     setSpannerCount(side, spannerCount(side) - 1);
     break;
   case Side::Left: {
-    ColumnWidget *w = new ColumnWidget(this, firstColumn() - 1);
+    ColumnWidget *w = createColumnWidget(firstColumn() - 1);
 
     if (!columnInfo(w->column()).hidden)
       table_->setOffsets(table_->offset(Side::Left).toPixels()
@@ -502,7 +502,7 @@ void WTableView::addSection(const Side side)
     break;
   }
   case Side::Right: {
-    ColumnWidget *w = new ColumnWidget(this, lastColumn() + 1);
+    ColumnWidget *w = createColumnWidget(lastColumn() + 1);
 
     if (columnInfo(w->column()).hidden)
       w->hide();
@@ -782,7 +782,7 @@ void WTableView::reset()
   headerColumnsTable_->clear();
 
   for (int i = 0; i < rowHeaderCount(); ++i)
-    new ColumnWidget(this, i);
+    createColumnWidget(i);
 }
 
 void WTableView::defineJavaScript()
@@ -1144,30 +1144,36 @@ bool WTableView::isColumnRendered(const int column) const
   return column >= firstColumn() && column <= lastColumn();
 }
 
-WTableView::ColumnWidget::ColumnWidget(WTableView *view, int column)
-  : column_(column)
+WTableView::ColumnWidget *WTableView::createColumnWidget(int column)
 {
-  assert(view->ajaxMode());
+  assert(ajaxMode());
 
-  WTableView::ColumnInfo& ci = view->columnInfo(column);
-  setStyleClass(ci.styleClass());
-  setPositionScheme(PositionScheme::Absolute);
-  setOffsets(0, Side::Top | Side::Left);
-  setOverflow(Overflow::Hidden);
-  setHeight(view->table_->height());
+  ColumnWidget *result = new ColumnWidget(column);
+  std::unique_ptr<ColumnWidget> columnWidget(result);
 
-  std::unique_ptr<WWidget> self(this);
+  WTableView::ColumnInfo& ci = columnInfo(column);
+  columnWidget->setStyleClass(ci.styleClass());
+  columnWidget->setPositionScheme(PositionScheme::Absolute);
+  columnWidget->setOffsets(0, Side::Top | Side::Left);
+  columnWidget->setOverflow(Overflow::Hidden);
+  columnWidget->setHeight(table_->height());
 
-  if (column >= view->rowHeaderCount()) {
-    if (view->table_->count() == 0
-	|| column > view->columnContainer(-1)->column())
-      view->table_->addWidget(std::move(self));
+  if (column >= rowHeaderCount()) {
+    if (table_->count() == 0
+        || column > columnContainer(-1)->column())
+      table_->addWidget(std::move(columnWidget));
     else
-      view->table_->insertWidget(0, std::move(self));
+      table_->insertWidget(0, std::move(columnWidget));
   } else
-    view->headerColumnsTable_->insertWidget(column, std::move(self));
+    headerColumnsTable_->insertWidget(column, std::move(columnWidget));
+
+  return result;
 }
 
+WTableView::ColumnWidget::ColumnWidget(int column)
+  : column_(column)
+{ }
+
 WTableView::ColumnWidget *WTableView::columnContainer(int renderedColumn) const
 {
   assert(ajaxMode());

src/Wt/WTableView.h

@@ -174,14 +174,21 @@ class WT_API WTableView : public WAbstractItemView
   virtual void enableAjax() override;
 
 private:
+  class ColumnWidget;
+
+  ColumnWidget *createColumnWidget(int column);
+
   class ColumnWidget : public WContainerWidget
   {
   public:
-    ColumnWidget(WTableView *view, int column);
     int column() const { return column_; }
 
   private:
+    ColumnWidget(int column);
+
     int column_;
+
+    friend ColumnWidget *WTableView::createColumnWidget(int column);
   };
 
   /* For Ajax implementation */