How can I evaluate an argument in a preprocessor macro to pass to sizeof?

I want to have a function that prints out information about a member variable of a struct. In order to keep the function as simple (and error free) as possible I dont want to manually pass in the type as well. This causes me to need to be able to evaluate the arguments passed into my macro:

#ifndef preprocessor_stringify
#define preprocessor_stringify(s) #s
#endif

typedef struct test_s {
    void (*ptr)(void*);
} test;

void doSomething_(char *name, int offset, int size){
    printf("%s %d %d\n", name, offset, size);
}

#define doSomething(name, container) (\
    doSomething_(\
        preprocessor_stringify(name),\
        offsetof(container, name),\
        sizeof(container->name))\
    );

int main(){
    doSomething(ptr, test);
    return 0;
}

This yields a compile error of test.cpp:21:19: error: expected primary-expression before ‘->’ token sizeof(container->name))\

Any ideas on how to fix this? I would like the solution to be both c and c++ compatible, ideally.