Is it a good idea to use C# for GUI and C++ for functions in same project?

Question

It is because, i'm thinking of trying to make a little program, where I will make a GUI and some functions for that, but I have readed on the internet, and found many discussions about whether to use C# or C++ for the GUI or should I use the same language for GUI and functions?

Answer 1

https://stackoverflow.com/questions/2532907/combining-c-and-c-sharp