Add QDebug::toString()

This template function streams the given object into a QDebug instance
that operates on a string, and then returns that string.

This function is useful for cases where you need the textual
representation of an object for debugging, but cannot use operator<<.
A good example of this is when writing tests where you want to provide
a useful failure message involving details about an object, but must
provide it in a string to e.g. QVERIFY2.

[ChangeLog][QtCore][QDebug] Added static template toString() function,
which streams the given object into a QDebug instance that operates on
a string, and then returns that string.

Fixes: QTBUG-82309
Change-Id: I8411394e899dedad19cec788d779a4515d52ba11
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 18 insertions, 0 deletions

diff --git a/src/corelib/io/qdebug.h b/src/corelib/io/qdebug.h
index 2314b36bda..9a6abc1994 100644
--- a/src/corelib/io/qdebug.h
+++ b/src/corelib/io/qdebug.h
@@ -173,6 +173,24 @@ public:
 
     inline QDebug &operator<<(QTextStreamManipulator m)
     { stream->ts << m; return *this; }
+
+    template <typename T>
+    static QString toString(const T &object)
+    {
+        QString buffer;
+        QDebug stream(&buffer);
+        stream << object;
+        return buffer;
+    }
+
+    template <typename T>
+    static QString toString(const T *object)
+    {
+        QString buffer;
+        QDebug stream(&buffer);
+        stream << object;
+        return buffer;
+    }
 };
 
 Q_DECLARE_SHARED(QDebug)