QVector: add relational operators <,<=,>,>=

std::vector has them, too.

[ChangeLog][QtCore][QVector] Added relational operators <, <=, >, >= if the element
type supports operator<.

Change-Id: I0bcb22dfcc43cb0362f17b4e06154ce18646580a
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/src/corelib/tools/qvector.h b/src/corelib/tools/qvector.h
index a48269cfaa..c8210281a7 100644
--- a/src/corelib/tools/qvector.h
+++ b/src/corelib/tools/qvector.h
@@ -865,6 +865,36 @@ QList<T> QList<T>::fromVector(const QVector<T> &vector)
 Q_DECLARE_SEQUENTIAL_ITERATOR(Vector)
 Q_DECLARE_MUTABLE_SEQUENTIAL_ITERATOR(Vector)
 
+template <typename T>
+bool operator<(const QVector<T> &lhs, const QVector<T> &rhs)
+    Q_DECL_NOEXCEPT_EXPR(noexcept(std::lexicographical_compare(lhs.begin(), lhs.end(),
+                                                               rhs.begin(), rhs.end())))
+{
+    return std::lexicographical_compare(lhs.begin(), lhs.end(),
+                                        rhs.begin(), rhs.end());
+}
+
+template <typename T>
+inline bool operator>(const QVector<T> &lhs, const QVector<T> &rhs)
+    Q_DECL_NOEXCEPT_EXPR(noexcept(lhs < rhs))
+{
+    return rhs < lhs;
+}
+
+template <typename T>
+inline bool operator<=(const QVector<T> &lhs, const QVector<T> &rhs)
+    Q_DECL_NOEXCEPT_EXPR(noexcept(lhs < rhs))
+{
+    return !(lhs > rhs);
+}
+
+template <typename T>
+inline bool operator>=(const QVector<T> &lhs, const QVector<T> &rhs)
+    Q_DECL_NOEXCEPT_EXPR(noexcept(lhs < rhs))
+{
+    return !(lhs < rhs);
+}
+
 /*
    ### Qt 5:
    ### This needs to be removed for next releases of Qt. It is a workaround for vc++ because