Doc: Compile textdocument-end snippets

* Extend GUI snippet compilation with textdocument-end snippet.
* Rename the snippet file and replace main() with wrapper().
* Dedent the snippet itself.
* Update documentation that includes the snippet.

Done-with: Nico Vertriest <nico.vertriest@qt.io>
Task-number: QTBUG-81486
Change-Id: Id5e5b284587da1e7fdfd00baa9c899626832a113
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

src/gui/doc/snippets/snippets.pro

@@ -3,6 +3,6 @@ SUBDIRS =
 
 contains(QT_BUILD_PARTS, tests) {
     SUBDIRS += \
-        qfontdatabase
+        qfontdatabase \
+        textdocument-end
 }
-

src/gui/doc/snippets/textdocument-end/textdocumentend_snippet.pro

@@ -0,0 +1,5 @@
+TEMPLATE = lib
+TARGET = textdocumentend_snippets
+QT += core gui widgets
+
+SOURCES = textdocumentendsnippet.cpp

src/gui/doc/snippets/textdocument-end/textdocumentendsnippet.cpp

@@ -49,18 +49,18 @@
 ****************************************************************************/
 
 #include <QtGui>
-#include <iostream.h>
+#include <iostream>
 
-int main(int argv, char **args)
+namespace textdocumentendsnippet {
+void wrapper()
 {
     QString contentString("One\nTwp\nThree");
-
     QTextDocument *doc = new QTextDocument(contentString);
 
 //! [0]
-    for (QTextBlock it = doc->begin(); it != doc->end(); it = it.next())
-        cout << it.text().toStdString() << Qt::endl;
+for (QTextBlock it = doc->begin(); it != doc->end(); it = it.next())
+    std::cout << it.text().toStdString() << "\n";
 //! [0]
 
-    return 0;
-}
+} // wrapper
+} //textdocumentendsnippet

src/gui/text/qtextdocument.cpp

@@ -1642,7 +1642,7 @@ QTextBlock QTextDocument::begin() const
     This function returns a block to test for the end of the document
     while iterating over it.
 
-    \snippet textdocumentendsnippet.cpp 0
+    \snippet textdocument-end/textdocumentendsnippet.cpp 0
 
     The block returned is invalid and represents the block after the
     last block in the document. You can use lastBlock() to retrieve the