Currently the naming of methods and functions in lib.rs is inconsistent:

• type_name
• HandleGeomCurve_Value
• DynamicType

Proposal:

Naming

1. Always use the Opencascade convention for C++. (CammelCase with no _, including standalone functions). Not the rust convention.

type_name(...) -> TypeName(...)

2. Since cxx has no better way yet, use _ to show associated types for functions that cant be bound using self. This covers constructors and other similar functions.

HandleGeomCurve_Value

3. In lib.rs, since it is in rust, we always use rust naming conventions and make use of the cxx_name attribute to point to the correct c++ method.

#[cxx_name = "Shape"]
pub fn shape(self: Pin<&mut BRepAlgoAPI_Fuse>) -> &TopoDS_Shape;

Access

Free floating functions are hard to reason about. Since Opencascade is a class based library, we should follow the same by re-attaching methods to the respective parent. If a function is associated with a type it should be private and attached via an impl block to the associated type.

...
    type StlAPI_Writer;
    fn StlAPI_Writer_ctor() -> UniquePtr<StlAPI_Writer>;
  }
}
...

impl ffi::StlAPI_Writer {
    pub fn new() -> cxx::UniquePtr<ffi::StlAPI_Writer> {
        ffi::StlAPI_Writer_ctor()
    }
}

What do you think? I feel this will be a good step forward and help reason about how future additions to the -sys crate should be made.