In C++, duck typing (structural typing) could be represented explicitly using type erasure (explicit in how you have to declare what the structure is) or using

In C++, duck typing (structural typing) could be represented explicitly using type erasure (explicit in how you have to declare what the structure is) or using templates, which do not require declaration of the structure beyond the actual use in code (though concepts allow you provide structure requirements). Templates result in code being generated for each set of template arguments used. Type erasure does not - or at least not nearly as much (the constructors of the type-erased type almost certainly use templates). In this way, the type erasure approach most closely resembles the behavior of Python (virtual calls), while the template approach most closely resembles the style of Python (no declaration of structure required). There is no ideal way to get both the behavior and style of Python, but you can get pretty close by passing only one type of type-erased type to a function template - only one template function will be produced, which would make calls to virtual functions.