Returning const arrays forces a copy

* This doesn't cover all cases but helps with 'pythonic' cases where a list
  returned from a function should be expected to be mutable. Modifying direct
  'members' can still modify through const.

qrenderdoc/Code/CaptureContext.h

@@ -155,8 +155,8 @@ public:
   ResultDetails GetFatalError() override { return m_Replay.GetFatalError(); }
   rdcstr GetCaptureFilename() override { return m_CaptureFile; }
   CaptureModifications GetCaptureModifications() override { return m_CaptureMods; }
-  const FrameDescription &FrameInfo() override { return m_FrameInfo; }
-  const APIProperties &APIProps() override { return m_APIProps; }
+  FrameDescription FrameInfo() override { return m_FrameInfo; }
+  APIProperties APIProps() override { return m_APIProps; }
   rdcarray<ShaderEncoding> CustomShaderEncodings() override { return m_CustomEncodings; }
   rdcarray<ShaderSourcePrefix> CustomShaderSourcePrefixes() override { return m_CustomPrefixes; }
   rdcarray<ShaderEncoding> TargetShaderEncodings() override { return m_TargetEncodings; }

qrenderdoc/Code/Interface/QRDInterface.h

@@ -2166,14 +2166,14 @@ the UI which aren't reflected in the capture file on disk.
 :return: The frame information.
 :rtype: renderdoc.FrameDescription
 )");
-  virtual const FrameDescription &FrameInfo() = 0;
+  virtual FrameDescription FrameInfo() = 0;
 
   DOCUMENT(R"(Retrieve the :class:`~renderdoc.APIProperties` for the currently loaded capture.
 
 :return: The API properties.
 :rtype: renderdoc.APIProperties
 )");
-  virtual const APIProperties &APIProps() = 0;
+  virtual APIProperties APIProps() = 0;
 
   DOCUMENT(R"(Retrieve the list of :class:`~renderdoc.ShaderEncoding` that are available for
 building target shaders for the currently loaded capture. See

qrenderdoc/Code/pyrenderdoc/container_handling.i

@@ -328,6 +328,10 @@ void ARRAY_INSTANTIATION_CHECK_NAME(typeName)(typeName<innerType> *);
 %typemap(ret) typeName & { ARRAY_INSTANTIATION_CHECK_NAME(typeName)($1); }
 %typemap(ret) typeName   { ARRAY_INSTANTIATION_CHECK_NAME(typeName)(&$1); }
 
+%typemap(out) typeName const & {
+  $result = ConvertToPy(indirect($1));
+}
+
 %enddef
 
 %define NON_TEMPLATE_ARRAY_INSTANTIATE(typeName)

qrenderdoc/Code/pyrenderdoc/renderdoc.i

@@ -98,6 +98,13 @@ VA_IGNORE_REST_OF_FILE
   PyDateTime_IMPORT;
 %}
 
+%typemap(out) const SWIGTYPE & {
+  static_assert(false, "Const ref types must be explicitly allowed, to ensure proper copy semantics. " \
+                       "Consider returning by copy if reasonable, or explicitly set up copy typemap.");
+  //$ltype owned = new std::remove_pointer<$ltype>::type(indirect($1));
+  //$result = SWIG_NewPointerObj(SWIG_as_voidptr(owned), $descriptor, SWIG_POINTER_OWN |  0 );
+}
+
 %include "pyconversion.i"
 
 // typemaps for windowing data
@@ -232,6 +239,17 @@ VA_IGNORE_REST_OF_FILE
   $1.assign(*$input);
 }
 
+// this is fine to return directly as it offers no mutable members
+%typemap(out) const PipeState & {
+  $result = SWIG_NewPointerObj(SWIG_as_voidptr($1), $descriptor, 0 );
+}
+
+// this is returned directly due to the size of the data contained in the type.
+// it's mostly "pythonic" to have an object returned that is considered mutable
+%typemap(out) const SDFile & {
+  $result = SWIG_NewPointerObj(SWIG_as_voidptr($1), $descriptor, 0 );
+}
+
 %typemap(ret) const ActionDescription * {
   // for ActionDescription pointers don't apply parent tracking, since these are preserved
   // in other ways and the linked-list nature of walking them can produce absurdly long