Solution to functions that tries modifying immutable arguments passed by reference

Hello,

Have you found any solution for handling functions that return values via output parameters passed by reference, especially when those parameters are of immutable types?

This becomes a problem with important functions like [BRep_Tool::CurveOnSurface](https://dev.opencascade.org/doc/occt-7.2.0/refman/html/class_b_rep___tool.html#aeaa70c29f0a30d827fd8a36116d74b91). In such cases, the function modifies the arguments passed by reference (e.g., to return the first and last parameters of the Geom2d_Curve), but when these are immutable types in the binding language, we can’t retrieve the modified values.

This effectively blocks access to important return data.

Some relevant references:

[pybind11 FAQ – Limitations involving reference arguments](https://pybind11.readthedocs.io/en/stable/faq.html#limitations-involving-reference-arguments)

[pyOCCT developer notes – Reference arguments](https://pyocct.readthedocs.io/en/latest/dev.html#reference-arguments)

Would appreciate any guidance or workarounds!

Thanks in advance.

从 BRep_Tool::CurveOnSurface 开始，查阅链接的 pybind11 FAQ 和关于引用参数的 pyOCCT 开发者说明。确定在 binding 层面公开已修改的曲线首尾参数所需的范围，然后验证调用方可以获取这些值。

由索引模型根据 Issue 内容生成。