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, 11 insertions, 0 deletions

diff --git a/src/corelib/tools/qset.qdoc b/src/corelib/tools/qset.qdoc
index 48863f2399..2e7a5a29ce 100644
--- a/src/corelib/tools/qset.qdoc
+++ b/src/corelib/tools/qset.qdoc
@@ -113,6 +113,17 @@
     compiled in C++11 mode.
 */
 
+/*! \fn template <class T> template<typename InputIterator> QSet<T>::QSet(InputIterator first, InputIterator last)
+    \since 5.14
+
+    Constructs a set with the contents in the iterator range [\a first, \a last).
+
+    The value type of \c InputIterator must be convertible to \c T.
+
+    \note If the range [\a first, \a last) contains duplicate elements,
+    the first one is retained.
+*/
+
 /*!
     \fn template <class T> void QSet<T>::swap(QSet<T> &other)