How to create TopTools_ListOfShape of two or more shapes in OpenCASCADE

TopTools_ListOfShape is just another name for NCollection_List<TopoDS_Shape>.

Using my OCCUtils library this is really easy:

#include <TopTools_ListOfShape.hxx>
#include <occutils/ListUtils.hxx>

using namespace OCCUtils;

/* ... */

TopoDS_Solid solid1 = /* ... */;
TopoDS_Solid solid2 = /* ... */;

TopTools_ListOfShape shapes = ListUtils::ToOCCList({solid1, solid2});

ListUtils::ToOCCList() takes almost anything as an argument, a std::initializer_list (this is the bracket syntax from the example above) but also any type of STL container like a std::vector or a std::list, and converts it into a NCollection_List<T>:

#include <TopTools_ListOfShape.hxx>
#include <occutils/ListUtils.hxx>
#include <vector>

using namespace OCCUtils;

/* ... */

TopoDS_Solid solid1 = /* ... */;
TopoDS_Solid solid2 = /* ... */;

std::vector<TopoDS_Shape> shapeVector({solid1, solid2});

TopTools_ListOfShape shapes = ListUtils::ToOCCList(shapeVector);

In case you don’t want to use OCCUtils, this is how you can create a TopTools_ListOfShape manually:

TopTools_ListOfShape list;
list.Append(shape1);
list.Append(shape2);

Since NCollection_List and therefore also TopTools_ListOfShape is a linked list internally, you can also use list.Prepend(shape); to add a shape to the front of the list without any performance penalty.

In case you want to create the list from a std::vector or any similar STL container, use this snippet:

std::vector<TopoDS_Shape>& shapeVector = /* ... */;

TopTools_ListOfShape list;
for(const TopoDS_Shape& shape : shapeVector) {
    list.Append(arg);
}

After creating the container, you can iterate it using the C++11 range-based for-loop:

TopTools_ListOfShape myShapes = /* ... */;

// Iterate myShapes
for(const TopoDS_Shape& shape : myShapes) {
    /* ... */
}

See How to iterate TopTools_ListOfShape in OpenCASCADE and How to iterate NCollection_List in OpenCASCADE for more details on that.