shiboken6: Add opaque containers for C++ sequence containers

Add a class that directly wraps a C++ sequence container,
allow for modifying them.

For all instantiated containers, generate a special (sequence) type
that wraps the C++ container directly. For example, it will be
accessible as a QList_int.

This is achieved via providing a template for a type private
that relies on a conversion traits template for conversion.
Only the  conversion traits specialization code needs to be generated.

Use cases:
- Allowing for modifying Fields of such container types
  (non-owning)
- Pass it into functions taking such containers instead of converting
  back and forth from a PyList (constructed in Python, owning)

[ChangeLog][shiboken6] Support for opaque C++ sequence scontainers
has been added, allowing to pass a wrapped C++ container
directly instead of converting it back and forth from
Python sequences.

Task-number: PYSIDE-1605
Change-Id: I49d378eb1a0151730d817d5bdd4b71a7c3b5cdda
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

2 files changed, 30 insertions, 3 deletions

diff --git a/sources/shiboken6/tests/minimalbinding/listuser_test.py b/sources/shiboken6/tests/minimalbinding/listuser_test.py
index b5048aa44..1a11ccfbf 100644
--- a/sources/shiboken6/tests/minimalbinding/listuser_test.py
+++ b/sources/shiboken6/tests/minimalbinding/listuser_test.py
@@ -39,7 +39,7 @@ sys.path.append(os.fspath(Path(__file__).resolve().parents[1]))
 from shiboken_paths import init_paths
 init_paths()
 
-from minimal import ListUser, Val, Obj
+from minimal import ListUser, Val, Obj, StdIntList
 
 
 class ExtListUser(ListUser):
@@ -321,6 +321,30 @@ class ListOfIntListConversionTest(unittest.TestCase):
         self.assertEqual(lu.sumListOfIntLists(lst), sum([sum(line) for line in [range(4)] * 4]) * 2)
         self.assertEqual(lu.callSumListOfIntLists(lst), sum([sum(line) for line in [range(4)] * 4]) * 2)
 
+    def testOpaqueContainer(self):
+        lu = ListUser()
+
+        # Set via Python
+        python_list = [1,2]
+        lu.setStdIntList(python_list)
+        self.assertEqual(len(lu.m_stdIntList), 2)
+        self.assertEqual(lu.m_stdIntList[0], 1)
+        self.assertEqual(lu.m_stdIntList[1], 2)
+
+        # Set via C++
+        cpp_list = StdIntList()
+        cpp_list.append(3)
+        cpp_list.append(4)
+        lu.setStdIntList(cpp_list)
+        self.assertEqual(len(lu.m_stdIntList), 2)
+        self.assertEqual(lu.m_stdIntList[0], 3)
+        self.assertEqual(lu.m_stdIntList[1], 4)
+
+        # Access field directly via reference
+        lu.m_stdIntList.append(5)
+        self.assertEqual(len(lu.m_stdIntList), 3)
+        self.assertEqual(lu.m_stdIntList[2], 5)
+
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/sources/shiboken6/tests/minimalbinding/typesystem_minimal.xml b/sources/shiboken6/tests/minimalbinding/typesystem_minimal.xml
index 625615fa1..2b9cbc89f 100644
--- a/sources/shiboken6/tests/minimalbinding/typesystem_minimal.xml
+++ b/sources/shiboken6/tests/minimalbinding/typesystem_minimal.xml
@@ -17,7 +17,8 @@
         </conversion-rule>
     </primitive-type>
 
-    <container-type name="std::list" type="list">
+    <container-type name="std::list" type="list"
+                    opaque-containers="int:StdIntList">
         <include file-name="list" location="global"/>
         <conversion-rule>
             <native-to-target>
@@ -47,7 +48,9 @@
     <value-type name="Val">
         <enum-type name="ValEnum"/>
     </value-type>
-    <value-type name="ListUser"/>
+    <value-type name="ListUser">
+        <modify-field name="m_stdIntList" opaque-container="yes"/>
+    </value-type>
     <value-type name="MinBoolUser"/>
 
     <container-type name="std::vector" type="vector">