https://stackoverflow.com/questions/71263885

cgoptr.go

package main

/*
#include <stdio.h>

struct real_client {
	int x;
};

typedef struct Client{
    struct real_client c;
} Client;

int doSomething(struct real_client *c) {
	printf("%d\n", c->x);
}

*/
import "C"

type Client struct {
	client C.Client
}

func main() {
	cl := Client{}
	cl.client.c.x = 42
	C.doSomething(&cl.client.c)
}

go.mod

module whatever

go 1.15

session.txt

cgoptr$ ~/devel/golang-1.16.13/bin/go build
cgoptr$  GODEBUG=cgocheck=2 ./whatever 
42