QVector/QList/QLinkedList/QVarLengthArray/QSet: add missing deduction guides

Amends 2e1763d83a1dacfc5b747934fb77fa7cec7bfe47.

The new range ctors need deduction guides, since the compiler can't
deduce the value_type from a pair of iterators.

Change-Id: I3ec1e5f91305b317c443b6a70246be416b55bad9
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

15 files changed, 186 insertions, 0 deletions

diff --git a/src/corelib/tools/qlinkedlist.h b/src/corelib/tools/qlinkedlist.h
index 996a50fd1b..8970d39be0 100644
--- a/src/corelib/tools/qlinkedlist.h
+++ b/src/corelib/tools/qlinkedlist.h
@@ -275,6 +275,13 @@ private:
 template <typename T>
 Q_DECLARE_TYPEINFO_BODY(QLinkedList<T>, Q_MOVABLE_TYPE|Q_RELOCATABLE_TYPE);
 
+#if defined(__cpp_deduction_guides) && __cpp_deduction_guides >= 201606
+template <typename InputIterator,
+          typename ValueType = typename std::iterator_traits<InputIterator>::value_type,
+          QtPrivate::IfIsInputIterator<InputIterator> = true>
+QLinkedList(InputIterator, InputIterator) -> QLinkedList<ValueType>;
+#endif
+
 template <typename T>
 inline QLinkedList<T>::~QLinkedList()
 {
diff --git a/src/corelib/tools/qlist.h b/src/corelib/tools/qlist.h
index 70bbc11ad2..471e16886f 100644
--- a/src/corelib/tools/qlist.h
+++ b/src/corelib/tools/qlist.h
@@ -446,6 +446,13 @@ private:
     inline int count_impl(const T &, QListData::ArrayCompatibleLayout) const;
 };
 
+#if defined(__cpp_deduction_guides) && __cpp_deduction_guides >= 201606
+template <typename InputIterator,
+          typename ValueType = typename std::iterator_traits<InputIterator>::value_type,
+          QtPrivate::IfIsInputIterator<InputIterator> = true>
+QList(InputIterator, InputIterator) -> QList<ValueType>;
+#endif
+
 #if defined(Q_CC_BOR)
 template <typename T>
 Q_INLINE_TEMPLATE T &QList<T>::Node::t()
diff --git a/src/corelib/tools/qset.h b/src/corelib/tools/qset.h
index 19d6982133..2e72832185 100644
--- a/src/corelib/tools/qset.h
+++ b/src/corelib/tools/qset.h
@@ -269,6 +269,13 @@ private:
     }
 };
 
+#if defined(__cpp_deduction_guides) && __cpp_deduction_guides >= 201606
+template <typename InputIterator,
+          typename ValueType = typename std::iterator_traits<InputIterator>::value_type,
+          QtPrivate::IfIsInputIterator<InputIterator> = true>
+QSet(InputIterator, InputIterator) -> QSet<ValueType>;
+#endif
+
 template <typename T>
 uint qHash(const QSet<T> &key, uint seed = 0)
 noexcept(noexcept(qHashRangeCommutative(key.begin(), key.end(), seed)))
diff --git a/src/corelib/tools/qvarlengtharray.h b/src/corelib/tools/qvarlengtharray.h
index 2f62526076..253d05ba2b 100644
--- a/src/corelib/tools/qvarlengtharray.h
+++ b/src/corelib/tools/qvarlengtharray.h
@@ -265,6 +265,13 @@ private:
     }
 };
 
+#if defined(__cpp_deduction_guides) && __cpp_deduction_guides >= 201606
+template <typename InputIterator,
+          typename ValueType = typename std::iterator_traits<InputIterator>::value_type,
+          QtPrivate::IfIsInputIterator<InputIterator> = true>
+QVarLengthArray(InputIterator, InputIterator) -> QVarLengthArray<ValueType>;
+#endif
+
 template <class T, int Prealloc>
 Q_INLINE_TEMPLATE QVarLengthArray<T, Prealloc>::QVarLengthArray(int asize)
     : s(asize) {
diff --git a/src/corelib/tools/qvector.h b/src/corelib/tools/qvector.h
index ebe6527d89..62fbdb4a2a 100644
--- a/src/corelib/tools/qvector.h
+++ b/src/corelib/tools/qvector.h
@@ -326,6 +326,13 @@ private:
     class AlignmentDummy { Data header; T array[1]; };
 };
 
+#if defined(__cpp_deduction_guides) && __cpp_deduction_guides >= 201606
+template <typename InputIterator,
+          typename ValueType = typename std::iterator_traits<InputIterator>::value_type,
+          QtPrivate::IfIsInputIterator<InputIterator> = true>
+QVector(InputIterator, InputIterator) -> QVector<ValueType>;
+#endif
+
 #ifdef Q_CC_MSVC
 // behavior change: an object of POD type constructed with an initializer of the form ()
 // will be default-initialized
diff --git a/tests/auto/corelib/tools/qlinkedlist/qlinkedlist.pro b/tests/auto/corelib/tools/qlinkedlist/qlinkedlist.pro
index 378c574eb0..c53d553d6d 100644
--- a/tests/auto/corelib/tools/qlinkedlist/qlinkedlist.pro
+++ b/tests/auto/corelib/tools/qlinkedlist/qlinkedlist.pro
@@ -1,5 +1,7 @@
 CONFIG += testcase
 TARGET = tst_qlinkedlist
 QT = core testlib
+qtConfig(c++14): CONFIG += c++14
+qtConfig(c++1z): CONFIG += c++1z
 SOURCES = tst_qlinkedlist.cpp
 DEFINES -= QT_NO_LINKED_LIST
diff --git a/tests/auto/corelib/tools/qlinkedlist/tst_qlinkedlist.cpp b/tests/auto/corelib/tools/qlinkedlist/tst_qlinkedlist.cpp
index deb3b68c5c..df42b5dea9 100644
--- a/tests/auto/corelib/tools/qlinkedlist/tst_qlinkedlist.cpp
+++ b/tests/auto/corelib/tools/qlinkedlist/tst_qlinkedlist.cpp
@@ -187,6 +187,7 @@ private slots:
     void countInt() const;
     void countMovable() const;
     void countComplex() const;
+    void cpp17ctad() const;
     void emptyInt() const;
     void emptyMovable() const;
     void emptyComplex() const;
@@ -594,6 +595,33 @@ void tst_QLinkedList::countComplex() const
     QCOMPARE(liveCount, Complex::getLiveCount());
 }
 
+void tst_QLinkedList::cpp17ctad() const
+{
+#ifdef __cpp_deduction_guides
+#define QVERIFY_IS_LIST_OF(obj, Type) \
+    QVERIFY2((std::is_same<decltype(obj), QLinkedList<Type>>::value), \
+             QMetaType::typeName(qMetaTypeId<decltype(obj)::value_type>()))
+#define CHECK(Type, One, Two, Three) \
+    do { \
+        const Type v[] = {One, Two, Three}; \
+        QLinkedList v1 = {One, Two, Three}; \
+        QVERIFY_IS_LIST_OF(v1, Type); \
+        QLinkedList v2(v1.begin(), v1.end()); \
+        QVERIFY_IS_LIST_OF(v2, Type); \
+        QLinkedList v3(std::begin(v), std::end(v)); \
+        QVERIFY_IS_LIST_OF(v3, Type); \
+    } while (false) \
+    /*end*/
+    CHECK(int, 1, 2, 3);
+    CHECK(double, 1.0, 2.0, 3.0);
+    CHECK(QString, QStringLiteral("one"), QStringLiteral("two"), QStringLiteral("three"));
+#undef QVERIFY_IS_LIST_OF
+#undef CHECK
+#else
+    QSKIP("This test requires C++17 Constructor Template Argument Deduction support enabled in the compiler.");
+#endif
+}
+
 template<typename T>
 void tst_QLinkedList::empty() const
 {
diff --git a/tests/auto/corelib/tools/qlist/qlist.pro b/tests/auto/corelib/tools/qlist/qlist.pro
index 47f0140abb..118c607880 100644
--- a/tests/auto/corelib/tools/qlist/qlist.pro
+++ b/tests/auto/corelib/tools/qlist/qlist.pro
@@ -1,4 +1,6 @@
 CONFIG += testcase
 TARGET = tst_qlist
 QT = core testlib
+qtConfig(c++14): CONFIG += c++14
+qtConfig(c++1z): CONFIG += c++1z
 SOURCES = $$PWD/tst_qlist.cpp
diff --git a/tests/auto/corelib/tools/qlist/tst_qlist.cpp b/tests/auto/corelib/tools/qlist/tst_qlist.cpp
index 5a485e88d2..cc9a3a16d1 100644
--- a/tests/auto/corelib/tools/qlist/tst_qlist.cpp
+++ b/tests/auto/corelib/tools/qlist/tst_qlist.cpp
@@ -310,6 +310,7 @@ private slots:
     void lastComplex() const;
     void constFirst() const;
     void constLast() const;
+    void cpp17ctad() const;
     void beginOptimal() const;
     void beginMovable() const;
     void beginComplex() const;
@@ -864,6 +865,33 @@ void tst_QList::constLast() const
     QVERIFY(listCopy.isSharedWith(list));
 }
 
+void tst_QList::cpp17ctad() const
+{
+#ifdef __cpp_deduction_guides
+#define QVERIFY_IS_LIST_OF(obj, Type) \
+    QVERIFY2((std::is_same<decltype(obj), QList<Type>>::value), \
+             QMetaType::typeName(qMetaTypeId<decltype(obj)::value_type>()))
+#define CHECK(Type, One, Two, Three) \
+    do { \
+        const Type v[] = {One, Two, Three}; \
+        QList v1 = {One, Two, Three}; \
+        QVERIFY_IS_LIST_OF(v1, Type); \
+        QList v2(v1.begin(), v1.end()); \
+        QVERIFY_IS_LIST_OF(v2, Type); \
+        QList v3(std::begin(v), std::end(v)); \
+        QVERIFY_IS_LIST_OF(v3, Type); \
+    } while (false) \
+    /*end*/
+    CHECK(int, 1, 2, 3);
+    CHECK(double, 1.0, 2.0, 3.0);
+    CHECK(QString, QStringLiteral("one"), QStringLiteral("two"), QStringLiteral("three"));
+#undef QVERIFY_IS_LIST_OF
+#undef CHECK
+#else
+    QSKIP("This test requires C++17 Constructor Template Argument Deduction support enabled in the compiler.");
+#endif
+}
+
 template<typename T>
 void tst_QList::last() const
 {
diff --git a/tests/auto/corelib/tools/qset/qset.pro b/tests/auto/corelib/tools/qset/qset.pro
index d0c6337147..3ae4bc4805 100644
--- a/tests/auto/corelib/tools/qset/qset.pro
+++ b/tests/auto/corelib/tools/qset/qset.pro
@@ -1,6 +1,8 @@
 CONFIG += testcase
 TARGET = tst_qset
 QT = core testlib
+qtConfig(c++14): CONFIG += c++14
+qtConfig(c++1z): CONFIG += c++1z
 SOURCES = tst_qset.cpp
 
 DEFINES -= QT_NO_JAVA_STYLE_ITERATORS
diff --git a/tests/auto/corelib/tools/qset/tst_qset.cpp b/tests/auto/corelib/tools/qset/tst_qset.cpp
index 31b4c0449e..8a545712a2 100644
--- a/tests/auto/corelib/tools/qset/tst_qset.cpp
+++ b/tests/auto/corelib/tools/qset/tst_qset.cpp
@@ -54,6 +54,7 @@ private slots:
     void detach();
     void isDetached();
     void clear();
+    void cpp17ctad();
     void remove();
     void contains();
     void containsSet();
@@ -325,6 +326,33 @@ void tst_QSet::clear()
     QVERIFY(set2.size() == 0);
 }
 
+void tst_QSet::cpp17ctad()
+{
+#ifdef __cpp_deduction_guides
+#define QVERIFY_IS_SET_OF(obj, Type) \
+    QVERIFY2((std::is_same<decltype(obj), QSet<Type>>::value), \
+             QMetaType::typeName(qMetaTypeId<decltype(obj)::value_type>()))
+#define CHECK(Type, One, Two, Three) \
+    do { \
+        const Type v[] = {One, Two, Three}; \
+        QSet v1 = {One, Two, Three}; \
+        QVERIFY_IS_SET_OF(v1, Type); \
+        QSet v2(v1.begin(), v1.end()); \
+        QVERIFY_IS_SET_OF(v2, Type); \
+        QSet v3(std::begin(v), std::end(v)); \
+        QVERIFY_IS_SET_OF(v3, Type); \
+    } while (false) \
+    /*end*/
+    CHECK(int, 1, 2, 3);
+    CHECK(double, 1.0, 2.0, 3.0);
+    CHECK(QString, QStringLiteral("one"), QStringLiteral("two"), QStringLiteral("three"));
+#undef QVERIFY_IS_SET_OF
+#undef CHECK
+#else
+    QSKIP("This test requires C++17 Constructor Template Argument Deduction support enabled in the compiler.");
+#endif
+}
+
 void tst_QSet::remove()
 {
     QSet<QString> set1;
diff --git a/tests/auto/corelib/tools/qvarlengtharray/qvarlengtharray.pro b/tests/auto/corelib/tools/qvarlengtharray/qvarlengtharray.pro
index 108fb33db5..14b2bc213b 100644
--- a/tests/auto/corelib/tools/qvarlengtharray/qvarlengtharray.pro
+++ b/tests/auto/corelib/tools/qvarlengtharray/qvarlengtharray.pro
@@ -1,4 +1,6 @@
 CONFIG += testcase
 TARGET = tst_qvarlengtharray
 QT = core testlib
+qtConfig(c++14): CONFIG += c++14
+qtConfig(c++1z): CONFIG += c++1z
 SOURCES = tst_qvarlengtharray.cpp
diff --git a/tests/auto/corelib/tools/qvarlengtharray/tst_qvarlengtharray.cpp b/tests/auto/corelib/tools/qvarlengtharray/tst_qvarlengtharray.cpp
index 3d90644aa3..a1d0100f96 100644
--- a/tests/auto/corelib/tools/qvarlengtharray/tst_qvarlengtharray.cpp
+++ b/tests/auto/corelib/tools/qvarlengtharray/tst_qvarlengtharray.cpp
@@ -44,6 +44,7 @@ private slots:
     void realloc();
     void reverseIterators();
     void count();
+    void cpp17ctad();
     void first();
     void last();
     void squeeze();
@@ -717,6 +718,34 @@ void tst_QVarLengthArray::count()
     }
 }
 
+void tst_QVarLengthArray::cpp17ctad()
+{
+#ifdef __cpp_deduction_guides
+#define QVERIFY_IS_VLA_OF(obj, Type) \
+    QVERIFY2((std::is_same<decltype(obj), QVarLengthArray<Type>>::value), \
+             QMetaType::typeName(qMetaTypeId<decltype(obj)::value_type>()))
+#define CHECK(Type, One, Two, Three) \
+    do { \
+        const Type v[] = {One, Two, Three}; \
+        QVarLengthArray v1 = {One, Two, Three}; \
+        QVERIFY_IS_VLA_OF(v1, Type); \
+        QVarLengthArray v2(v1.begin(), v1.end()); \
+        QVERIFY_IS_VLA_OF(v2, Type); \
+        QVarLengthArray v3(std::begin(v), std::end(v)); \
+        QVERIFY_IS_VLA_OF(v3, Type); \
+    } while (false) \
+    /*end*/
+    CHECK(int, 1, 2, 3);
+    CHECK(double, 1.0, 2.0, 3.0);
+    CHECK(QString, QStringLiteral("one"), QStringLiteral("two"), QStringLiteral("three"));
+#undef QVERIFY_IS_VLA_OF
+#undef CHECK
+#else
+    QSKIP("This test requires C++17 Constructor Template Argument Deduction support enabled in the compiler.");
+#endif
+
+}
+
 void tst_QVarLengthArray::first()
 {
     // append some items, make sure it stays sane
diff --git a/tests/auto/corelib/tools/qvector/qvector.pro b/tests/auto/corelib/tools/qvector/qvector.pro
index b9a4ae747b..689d9b87a2 100644
--- a/tests/auto/corelib/tools/qvector/qvector.pro
+++ b/tests/auto/corelib/tools/qvector/qvector.pro
@@ -1,5 +1,7 @@
 CONFIG += testcase
 qtConfig(c++11): CONFIG += c++11
+qtConfig(c++14): CONFIG += c++14
+qtConfig(c++1z): CONFIG += c++1z
 TARGET = tst_qvector
 QT = core testlib
 SOURCES = $$PWD/tst_qvector.cpp
diff --git a/tests/auto/corelib/tools/qvector/tst_qvector.cpp b/tests/auto/corelib/tools/qvector/tst_qvector.cpp
index 05b5579d64..08d5a8cd50 100644
--- a/tests/auto/corelib/tools/qvector/tst_qvector.cpp
+++ b/tests/auto/corelib/tools/qvector/tst_qvector.cpp
@@ -230,6 +230,7 @@ private slots:
     void countInt() const;
     void countMovable() const;
     void countCustom() const;
+    void cpp17ctad() const;
     void data() const;
     void emptyInt() const;
     void emptyMovable() const;
@@ -914,6 +915,33 @@ void tst_QVector::countCustom() const
     QCOMPARE(instancesCount, Custom::counter.loadAcquire());
 }
 
+void tst_QVector::cpp17ctad() const
+{
+#ifdef __cpp_deduction_guides
+#define QVERIFY_IS_VECTOR_OF(obj, Type) \
+    QVERIFY2((std::is_same<decltype(obj), QVector<Type>>::value), \
+             QMetaType::typeName(qMetaTypeId<decltype(obj)::value_type>()))
+#define CHECK(Type, One, Two, Three) \
+    do { \
+        const Type v[] = {One, Two, Three}; \
+        QVector v1 = {One, Two, Three}; \
+        QVERIFY_IS_VECTOR_OF(v1, Type); \
+        QVector v2(v1.begin(), v1.end()); \
+        QVERIFY_IS_VECTOR_OF(v2, Type); \
+        QVector v3(std::begin(v), std::end(v)); \
+        QVERIFY_IS_VECTOR_OF(v3, Type); \
+    } while (false) \
+    /*end*/
+    CHECK(int, 1, 2, 3);
+    CHECK(double, 1.0, 2.0, 3.0);
+    CHECK(QString, QStringLiteral("one"), QStringLiteral("two"), QStringLiteral("three"));
+#undef QVERIFY_IS_VECTOR_OF
+#undef CHECK
+#else
+    QSKIP("This test requires C++17 Constructor Template Argument Deduction support enabled in the compiler.");
+#endif
+}
+
 void tst_QVector::data() const
 {
     QVector<int> myvec;