Fix source compatibility with existing toString() extensions

Pick-to: 6.8
Change-Id: I946ebf0f0fa82450105e720489c4da35a77078d8
Reviewed-by: Ivan Solovev <[email protected]>
Reviewed-by: Thiago Macieira <[email protected]>

3 files changed, 18 insertions, 19 deletions

diff --git a/src/testlib/qtestcase.cpp b/src/testlib/qtestcase.cpp
index 5648fedd639..1ffe283ce92 100644
--- a/src/testlib/qtestcase.cpp
+++ b/src/testlib/qtestcase.cpp
@@ -3144,7 +3144,16 @@ char *QTest::toString(const volatile QObject *vo)
     if (vo == nullptr)
         return qstrdup("<null>");
 
-    auto *o = const_cast<const QObject*>(vo);
+    return QTest::toString(const_cast<const QObject*>(vo));
+}
+
+/*! \internal
+*/
+char *QTest::toString(const QObject *o)
+{
+    if (o == nullptr)
+        return qstrdup("<null>");
+
     const QString &name = o->objectName();
     const char *className = o->metaObject()->className();
     char *msg = new char[256];
@@ -3155,6 +3164,7 @@ char *QTest::toString(const volatile QObject *vo)
     return msg;
 }
 
+
 /*! \fn char *QTest::toString(const QColor &color)
     \internal
 */
diff --git a/src/testlib/qtestcase.qdoc b/src/testlib/qtestcase.qdoc
index 6a067c351f8..7614f67312b 100644
--- a/src/testlib/qtestcase.qdoc
+++ b/src/testlib/qtestcase.qdoc
@@ -1423,7 +1423,7 @@
 */
 
 /*!
-    \fn template<typename T, QTest::Internal::is_suitable_type_v<T> = true> char *QTest::toString(const T &value)
+    \fn template <typename T> char *QTest::toString(const T &value)
 
     Returns a textual representation of \a value. This function is used by
     \l QCOMPARE() to output verbose information in case of a test failure.
diff --git a/src/testlib/qtesttostring.h b/src/testlib/qtesttostring.h
index a1ee4f69258..d5d48bb4f4e 100644
--- a/src/testlib/qtesttostring.h
+++ b/src/testlib/qtesttostring.h
@@ -81,19 +81,6 @@ inline typename std::enable_if<!QtPrivate::IsQEnumHelper<F>::Value, char*>::type
     return msg;
 }
 
-template <typename T>
-constexpr bool is_suitable_type_helper_v = std::disjunction_v<std::is_same<T, char>,
-                                                              std::is_same<T, void>,
-                                                              std::is_same<T, QObject>
-                                                             >;
-
-template <typename T>
-using is_suitable_type_v =
-    std::enable_if_t<!(std::is_pointer_v<T>
-                        && is_suitable_type_helper_v<
-                                   std::remove_const_t<std::remove_pointer_t<T>>>),
-                    bool>;
-
 } // namespace Internal
 
 Q_TESTLIB_EXPORT bool compare_string_helper(const char *t1, const char *t2, const char *actual,
@@ -102,11 +89,8 @@ Q_TESTLIB_EXPORT char *formatString(const char *prefix, const char *suffix, size
 Q_TESTLIB_EXPORT char *toHexRepresentation(const char *ba, qsizetype length);
 Q_TESTLIB_EXPORT char *toPrettyCString(const char *unicode, qsizetype length);
 Q_TESTLIB_EXPORT char *toPrettyUnicode(QStringView string);
-Q_TESTLIB_EXPORT char *toString(const char *);
-Q_TESTLIB_EXPORT char *toString(const volatile void *);
-Q_TESTLIB_EXPORT char *toString(const volatile QObject *);
 
-template<typename T, Internal::is_suitable_type_v<T> = true>
+template <typename T>
 inline char *toString(const T &t)
 {
     return Internal::toString(t);
@@ -121,6 +105,11 @@ inline char *toString(const std::tuple<Types...> &tuple);
 template <typename Rep, typename Period>
 inline char *toString(std::chrono::duration<Rep, Period> duration);
 
+Q_TESTLIB_EXPORT char *toString(const char *);
+Q_TESTLIB_EXPORT char *toString(const volatile void *);
+Q_TESTLIB_EXPORT char *toString(const QObject *);
+Q_TESTLIB_EXPORT char *toString(const volatile QObject *);
+
 #define QTEST_COMPARE_DECL(KLASS)\
     template<> Q_TESTLIB_EXPORT char *toString<KLASS >(const KLASS &);
 #ifndef Q_QDOC