Use c++ to create a channel through fd file descriptor, which APIs need to be called.

[ccnankai]

Iam a beginner. I am going to write a client in c++. But the tutorials in the example create channels in the form of gprc::CreateChannel(localhost::port). If I want to connect to server through .socket file, like grpc.Dial(xxx.socket) in golang, what should I do, is there any example.