Revamp QtConcurrent examples to C++11

I updated signals and slots and for each loops to the new syntax and
replaced most free functions with std::function.

Task-number: QTBUG-60641
Change-Id: I7693f81f71c7f53fcbe83189a0de2fb76ddf99a8
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 15 insertions, 12 deletions

diff --git a/examples/qtconcurrent/wordcount/main.cpp b/examples/qtconcurrent/wordcount/main.cpp
index a5f8909f34..ff7ea24ee7 100644
--- a/examples/qtconcurrent/wordcount/main.cpp
+++ b/examples/qtconcurrent/wordcount/main.cpp
@@ -65,15 +65,17 @@ using namespace QtConcurrent;
 /*
     Utility function that recursivily searches for files.
 */
-QStringList findFiles(const QString &startDir, QStringList filters)
+QStringList findFiles(const QString &startDir, const QStringList &filters)
 {
     QStringList names;
     QDir dir(startDir);
 
-    foreach (QString file, dir.entryList(filters, QDir::Files))
+    const auto files = dir.entryList(filters, QDir::Files);
+    for (const QString &file : files)
         names += startDir + '/' + file;
 
-    foreach (QString subdir, dir.entryList(QDir::AllDirs | QDir::NoDotAndDotDot))
+    const auto subdirs =  dir.entryList(QDir::AllDirs | QDir::NoDotAndDotDot);
+    for (const QString &subdir : subdirs)
         names += findFiles(startDir + '/' + subdir, filters);
     return names;
 }
@@ -83,17 +85,18 @@ typedef QMap<QString, int> WordCount;
 /*
     Single threaded word counter function.
 */
-WordCount singleThreadedWordCount(QStringList files)
+WordCount singleThreadedWordCount(const QStringList &files)
 {
     WordCount wordCount;
-    foreach (QString file, files) {
+    for (const QString &file : files) {
         QFile f(file);
         f.open(QIODevice::ReadOnly);
         QTextStream textStream(&f);
-        while (textStream.atEnd() == false)
-            foreach (const QString &word, textStream.readLine().split(' '))
+        while (!textStream.atEnd()) {
+            const auto words =  textStream.readLine().split(' ');
+            for (const QString &word : words)
                 wordCount[word] += 1;
-
+        }
     }
     return wordCount;
 }
@@ -109,9 +112,11 @@ WordCount countWords(const QString &file)
     QTextStream textStream(&f);
     WordCount wordCount;
 
-    while (textStream.atEnd() == false)
-        foreach (const QString &word, textStream.readLine().split(' '))
+    while (!textStream.atEnd()) {
+        const auto words =  textStream.readLine().split(' ');
+        for (const QString &word : words)
             wordCount[word] += 1;
+    }
 
     return wordCount;
 }
@@ -137,8 +142,6 @@ int main(int argc, char** argv)
 
     qDebug() << "warmup";
     {
-        QTime time;
-        time.start();
         WordCount total = singleThreadedWordCount(files);
     }