Non-associative containers: add range constructors

Something nice we'd like to detect for array-backed containers
is if the iterator passed is a Contiguous one; if the type is also
trivially copyable / Q_PRIMITIVE_TYPE, we could memcpy() the whole
range.

However, there's no trait in the Standard to detect contiguous
iterators (the best approximation would be detecting if the iterator
is actually a pointer). Also, it's probably not smart to do the work
now for QVector since QVector needs refactoring anyhow, and this work
will be lost.

QString and QByteArray are left in another commit.

[ChangeLog][QtCore][QVector] Added range constructor.

[ChangeLog][QtCore][QVarLengthArray] Added range constructor.

[ChangeLog][QtCore][QList] Added range constructor.

[ChangeLog][QtCore][QStringList] Added range constructor.

[ChangeLog][QtCore][QLinkedList] Added range constructor.

[ChangeLog][QtCore][QSet] Added range constructor.

Change-Id: I220edb796053c9c4d31a6dbdc7efc5fc0f6678f9
Reviewed-by: Milian Wolff <milian.wolff@kdab.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/tests/auto/corelib/tools/qstringlist/tst_qstringlist.cpp b/tests/auto/corelib/tools/qstringlist/tst_qstringlist.cpp
index 42bdf62a93..37368c3dfc 100644
--- a/tests/auto/corelib/tools/qstringlist/tst_qstringlist.cpp
+++ b/tests/auto/corelib/tools/qstringlist/tst_qstringlist.cpp
@@ -30,13 +30,17 @@
 #include <qregexp.h>
 #include <qregularexpression.h>
 #include <qstringlist.h>
+#include <qvector.h>
 
 #include <locale.h>
 
+#include <algorithm>
+
 class tst_QStringList : public QObject
 {
     Q_OBJECT
 private slots:
+    void constructors();
     void sort();
     void filter();
     void replaceInStrings();
@@ -66,6 +70,39 @@ private slots:
 
 extern const char email[];
 
+void tst_QStringList::constructors()
+{
+    {
+        QStringList list;
+        QVERIFY(list.isEmpty());
+        QCOMPARE(list.size(), 0);
+        QVERIFY(list == QStringList());
+    }
+    {
+        QString str = "abc";
+        QStringList list(str);
+        QVERIFY(!list.isEmpty());
+        QCOMPARE(list.size(), 1);
+        QCOMPARE(list.at(0), str);
+    }
+    {
+        QStringList list{ "a", "b", "c" };
+        QVERIFY(!list.isEmpty());
+        QCOMPARE(list.size(), 3);
+        QCOMPARE(list.at(0), "a");
+        QCOMPARE(list.at(1), "b");
+        QCOMPARE(list.at(2), "c");
+    }
+    {
+        const QVector<QString> reference{ "a", "b", "c" };
+        QCOMPARE(reference.size(), 3);
+
+        QStringList list(reference.cbegin(), reference.cend());
+        QCOMPARE(list.size(), reference.size());
+        QVERIFY(std::equal(list.cbegin(), list.cend(), reference.cbegin()));
+    }
+}
+
 void tst_QStringList::indexOf_regExp()
 {
     QStringList list;