Can typedef and struct be put inside a class like below? Thanks!

Code:
class classA {
private:
    typedef void(classA::*aFnPtr_t) (); //pointer-to-member function
    struct strctA {
        int a;
        int b[100];
    };
    typedef struct strctA strctA_t;
    typedef void (classA::*bFnPtr_t)(strctA_t*); //pointer-to-member function
...
}