AFAIK, no? You can return a pointer to a struct, and you can pass whole structs as arguments, but not, IIRC, return them from functions.
EDIT: Apparently you can, sort of, but not portably; how exactly it is defined to work depends on the compiler, and each compiler might define it differently. This means that if you’re using a library which returns a struct and your program use a different C compiler than the library used when it was compiled, your program will not work. I.e. there is no one defined stable ABI for functions returning structs.
Therefore I think it’s reasonable to regard it as impossible in practice.
