Doc: Remove irrelevant sections from "Signals & Slots"

- This article is not the right place to describe the low-level
  mechanisms of moc and qmake, or to discuss QMetaObject features that
  are unrelated to signals and slots.
- Most users never need to run moc directly.
- The current content only mentions qmake for moc automation, but CMake,
  QBS, and the Visual Studio Add-In can also do that.

In light of the above 3 points, let's simply link to the "Meta-Object
System" article for those who are interested in the behind-the-scenes
details.

Most of the content deleted by this patch are already discussed in
detail in the articles "The Meta-Object System" and "Using the Meta-
Object Compiler (moc)" (the former links to the latter). The exception
is Snippet 5 -- this is deleted without replacement because
qobject_cast() is a much safer alternative to QMetaObject::inherits()
with static_cast(), so we should encourage the former.

Change-Id: I638c888cedfcdfb818747edeb806213ebd54dfb6
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

1 files changed, 0 insertions, 17 deletions

diff --git a/src/corelib/doc/snippets/signalsandslots/signalsandslots.cpp b/src/corelib/doc/snippets/signalsandslots/signalsandslots.cpp
index 91cd3de9d2..357269bac0 100644
--- a/src/corelib/doc/snippets/signalsandslots/signalsandslots.cpp
+++ b/src/corelib/doc/snippets/signalsandslots/signalsandslots.cpp
@@ -38,8 +38,6 @@
 **
 ****************************************************************************/
 
-#include <QAbstractButton>
-
 #include "signalsandslots.h"
 
 //! [0]
@@ -66,19 +64,4 @@ int main()
 //! [3] //! [4]
     b.setValue(48);     // a.value() == 12, b.value() == 48
 //! [4]
-
-
-    QWidget *widget = reinterpret_cast<QWidget *>(new QObject(0));
-//! [5]
-    if (widget->inherits("QAbstractButton")) {
-        QAbstractButton *button = static_cast<QAbstractButton *>(widget);
-        button->toggle();
-//! [5] //! [6]
-    }
-//! [6]
-
-//! [7]
-    if (QAbstractButton *button = qobject_cast<QAbstractButton *>(widget))
-        button->toggle();
-//! [7]
 }