Python std::vector back-reference changes

Give reference in container_owner a more unique name (back_reference).
Change back-reference 'ret' typemap to have a function name so that they
are less unwittingly be used elsewhere where not intended.

Note that they can be overridden by users if needed using:

%extend std::vector {
%typemap(ret)
  value_type const& __getitem__,
  value_type const& front,
  value_type const& back
  { ...  }
}

These override the SWIG supplied versions because the SWIG supplied
typemaps use non-const value_type&, but the methods use const, so the
above have a higher precedence in the typemap search algorithm.

1 files changed, 6 insertions, 4 deletions

diff --git a/Lib/python/pycontainer.swg b/Lib/python/pycontainer.swg
index a2ee9522c..5c2a981ee 100644
--- a/Lib/python/pycontainer.swg
+++ b/Lib/python/pycontainer.swg
@@ -52,7 +52,7 @@ namespace swig {
   struct container_owner {
     // By default, do not add the back-reference (for value types)
     // Specialization below will check the reference for pointer types.
-    static bool reference(PyObject* child, PyObject* owner) {
+    static bool back_reference(PyObject* child, PyObject* owner) {
       return false;
     }
   };
@@ -66,7 +66,7 @@ namespace swig {
      *
      * returns whether the reference was set or not
      */
-    static bool reference(PyObject* child, PyObject* owner) {
+    static bool back_reference(PyObject* child, PyObject* owner) {
       SwigPyObject* swigThis = SWIG_Python_GetSwigThis(child);
       if (swigThis && (swigThis->own & SWIG_POINTER_OWN) != SWIG_POINTER_OWN) {
         PyObject_SetAttr(child, container_owner_attribute(), owner);
@@ -809,8 +809,10 @@ namespace swig
       return self->size();
     }
 
-    %typemap(ret, fragment="reference_container_owner", noblock=1) value_type& {
-      (void)swig::container_owner<swig::traits<$*1_ltype>::category>::reference($result, $self);
+    // Although __getitem__, front, back actually use a const value_type& return type, the typemaps below
+    // use non-const so that they can be easily overridden by users if necessary.
+    %typemap(ret, fragment="reference_container_owner", noblock=1) value_type& __getitem__, value_type& front, value_type& back {
+      (void)swig::container_owner<swig::traits<$*1_ltype>::category>::back_reference($result, $self);
     }
   }
 %enddef